Develop Reference

JavaScript helps with conditional syntax

I have a function that calls an API (let's call it API-1) to get the song lyrics.
Since this API sometimes can't find a song in its database, I want to call another API (let's call it API-2) to do the same search.
I need to integrate the code of both APIs inside the function, when the first one doesn't get data.
I tell you some very important information:
In API-1 I must force the data to be fetched as XML and the responseType must be 'document'.
API-2 does not require any of the above conditions, the data is parced as JSON and the responseType it supports is 'text', but does not require it to be set, with 'document' it DOES NOT work, it gives error.
Now I will share the function code for API-1 and then I will share the same function code for API-2.
They both work perfect if I test them independently.
The help I am asking for is to integrate API-2 when API-1 does not fetch data.
Code using API-1
this.refreshLyric = function (currentSong, currentArtist) {
var xhr = new XMLHttpRequest;
xhr.open('GET', proxy_URL + api_URL + 'apiv1.asmx/SearchLyricDirect?artist=' + currentArtistE + '&song=' + ucwords(currentSongE), true);
// ONLY FOR THIS XMLHttpRequest responseType must be empty string or 'document'
xhr.responseType = 'document';
// ONLY FOR THIS XMLHttpRequest force the response to be parsed as XML
xhr.overrideMimeType('text/xml');
xhr.onload = function () {
if (xhr.readyState === xhr.DONE && xhr.status === 200) {
var openLyric = document.getElementsByClassName('lyrics')[0];
var lyric = xhr.responseXML.getElementsByTagName('Lyric')[0].innerHTML;
//check if any data was obtained
if (lyric != '') {
document.getElementById('lyric').innerHTML = lyric.replace(/\n/g, '<br />');
openLyric.style.opacity = "1";
openLyric.setAttribute('data-toggle', 'modal');
} else { /////// HERE INTEGRATE API-2 //////
openLyric.style.opacity = "0.3";
openLyric.removeAttribute('data-toggle');
var modalLyric = document.getElementById('modalLyrics');
modalLyric.style.display = "none";
modalLyric.setAttribute('aria-hidden', 'true');
(document.getElementsByClassName('modal-backdrop')[0]) ? document.getElementsByClassName('modal-backdrop')[0].remove(): '';
}
} else {
document.getElementsByClassName('lyrics')[0].style.opacity = "0.3";
document.getElementsByClassName('lyrics')[0].removeAttribute('data-toggle');
}
};
xhr.send();
}
The same code using API-2
this.refreshLyric = function (currentSong, currentArtist) {
var xhttp = new XMLHttpRequest();
xhttp.onreadystatechange = function () {
if (this.readyState === 4 && this.status === 200) {
var data = JSON.parse(this.responseText);
var openLyric = document.getElementsByClassName('lyrics')[0];
var lyric = data.mus[0].text;
//check if any data was obtained
if (lyric != '') {
document.getElementById('lyric').innerHTML = lyric.replace(/\n/g, '<br />');
openLyric.style.opacity = "1";
openLyric.setAttribute('data-toggle', 'modal');
} else {
openLyric.style.opacity = "0.3";
openLyric.removeAttribute('data-toggle');
var modalLyric = document.getElementById('modalLyrics');
modalLyric.style.display = "none";
modalLyric.setAttribute('aria-hidden', 'true');
(document.getElementsByClassName('modal-backdrop')[0]) ? document.getElementsByClassName('modal-backdrop')[0].remove(): '';
}
} else {
document.getElementsByClassName('lyrics')[0].style.opacity = "0.3";
document.getElementsByClassName('lyrics')[0].removeAttribute('data-toggle');
}
}
xhttp.open('GET', 'https://api.vagalume.com.br/search.php?apikey=' + API_KEY + '&art=' + currentArtist + '&mus=' + currentSong.toLowerCase(), true);
xhttp.send()
}
The shared codes are of the SAME function (this.refreshLyric), what has to be integrated is only the XMLHttpRequest API.
In the ELSE of line 23 of API-1 I must integrate the code of API-2.
I have already tried it in several ways but I am presented with syntax problems with the IF - ELSE conditionals and errors with the API-2 which is getting the responseType and the MimeType of API-1.

EDIT
FIXED: When API-1 cannot find the lyric, I have created a new function that calls API-2. refreshLyric2(currentSong, currentArtist); :)
this.refreshLyric = function (currentSong, currentArtist) {
var xhr = new XMLHttpRequest;
xhr.open('GET', proxy_URL + api_URL + 'apiv1.asmx/SearchLyricDirect?artist=' + currentArtistE + '&song=' + ucwords(currentSongE), true);
// ONLY FOR THIS XMLHttpRequest responseType must be empty string or 'document'
xhr.responseType = 'document';
// ONLY FOR THIS XMLHttpRequest force the response to be parsed as XML
xhr.overrideMimeType('text/xml');
xhr.onload = function () {
if (xhr.readyState === xhr.DONE && xhr.status === 200) {
var openLyric = document.getElementsByClassName('lyrics')[0];
var lyric = xhr.responseXML.getElementsByTagName('Lyric')[0].innerHTML;
//check if any data was obtained
if (lyric != '') {
document.getElementById('lyric').innerHTML = lyric.replace(/\n/g, '<br />');
openLyric.style.opacity = "1";
openLyric.setAttribute('data-toggle', 'modal');
} else {
//If lyric was not obtained, we call API-2
refreshLyric2(currentSong, currentArtist);
}
} else {
document.getElementsByClassName('lyrics')[0].style.opacity = "0.3";
document.getElementsByClassName('lyrics')[0].removeAttribute('data-toggle');
}
};
xhr.send();
}
refreshLyric2 = function (currentSong, currentArtist) {
var xhttp = new XMLHttpRequest();
xhttp.onreadystatechange = function () {
if (this.readyState === 4 && this.status === 200) {
var data = JSON.parse(this.responseText);
var openLyric = document.getElementsByClassName('lyrics')[0];
var lyric = data.mus[0].text;
//check if any data was obtained
if (lyric != '') {
document.getElementById('lyric').innerHTML = lyric.replace(/\n/g, '<br />');
openLyric.style.opacity = "1";
openLyric.setAttribute('data-toggle', 'modal');
} else {
openLyric.style.opacity = "0.3";
openLyric.removeAttribute('data-toggle');
var modalLyric = document.getElementById('modalLyrics');
modalLyric.style.display = "none";
modalLyric.setAttribute('aria-hidden', 'true');
(document.getElementsByClassName('modal-backdrop')[0]) ? document.getElementsByClassName('modal-backdrop')[0].remove(): '';
}
} else {
document.getElementsByClassName('lyrics')[0].style.opacity = "0.3";
document.getElementsByClassName('lyrics')[0].removeAttribute('data-toggle');
}
}
xhttp.open('GET', 'https://api.vagalume.com.br/search.php?apikey=' + API_KEY + '&art=' + currentArtist + '&mus=' + currentSong.toLowerCase(), true);
xhttp.send()
}

how to fix javascript refresh error on google chrome

I have an error which is giving me a hard time to fix. I have written a program in JavaScript but when I refresh it doesn't affect the page. I even closed and opened the browser more than once but it didn't work, please does anyone have a solution to it?
This is some part of the code
var person = document.getElementById('formant');
var fname = document.getElementById('fname').value;
var lname = document.getElementById('lname').value;
var email = document.getElementById('email').value;
var num = document.getElementById('num').value;
var pass = document.getElementById('pass').value;
var conpass = document.getElementById('conpass').value;
var gen ='';
function setgen(f)
{
gen = document.getElementById(f).value;
}
person.addEventListener('submit', red);
function red(m)
{
m.preventDefault();
var xhr = new XMLHttpRequest();
// var response = document.getElementById().innerHTML;
xhr.open('POST','php/signupajax.php',true);
xhr.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
xhr.onload = function()
{
if(this.status == 200)
{
if(document.getElementById('pass').value.lenght < 0)
{
alert('less man');
}
console.log(this.responseText);
}
}
xhr.send('fname=' + document.getElementById('fname').value + '&lname=' + document.getElementById('lname').value + '&email=' + document.getElementById('email').value + '&num=' +document.getElementById('num').value+ '&pass=' + document.getElementById('pass').value + '&conpass=' +document.getElementById('conpass').value + '&gen=' + gen);
}
if(document.getElementById('pass').value <6)
{
alert('password not strong');
}
else{
alert('password good');
}

Run Javascript script from ajax response

I want to call a JS Script in Ajax response. What it does is pass the document.getElementById script to the Ajax responseText.
The current code returns me this error: Uncaught TypeError: Cannot set property 'innerHTML' of null
This is done with Visual Studio Cordova..
Ajax:
$("#loginBtn").click(function() {
var username = document.getElementById("username").value;
var password = document.getElementById("password").value;
var xmlhttp = new XMLHttpRequest();
xmlhttp.onreadystatechange = function () {
if (this.readyState == 4 && this.status == 200) {
document.write(this.responseText);
}
}
xmlhttp.open("POST", "http://www.sampleee.esy.es/login.php", true);
xmlhttp.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
xmlhttp.send("username=" + username + "&" + "password=" + password);
});
PHP:
if($count == 1){
echo "document.getElementById('alertBox').innerHTML = 'Login Success!';
document.getElementById('alertBox').className = 'alert alert-success';
document.getElementById('alertBox').style.display = 'block';
setTimeout(function () {
window.location.href = '../html/dashboard.html';
}, 1000);
";
}else{
echo "document.getElementById('alertBox').innerHTML = 'Invalid login details';
document.getElementById('alertBox').className = 'alert alert-danger';
document.getElementById('alertBox').style.display = 'block';
";
}

You can solve it by a small change, you just have to write JS code in the AJAX success that you wrote in your PHP page. In the PHP page, there is no alertBox element, that's why the error occurred.
Your JS code will be like this:
$("#loginBtn").click(function() {
var username = document.getElementById("username").value;
var password = document.getElementById("password").value;
var xmlhttp = new XMLHttpRequest();
xmlhttp.onreadystatechange = function () {
if (this.readyState == 4 && this.status == 200) {
if(this.responseText=="success"){
document.getElementById('alertBox').innerHTML = 'Login Success!';
document.getElementById('alertBox').className = 'alert alert-success';
document.getElementById('alertBox').style.display = 'block';
setTimeout(function () {
window.location.href = '../html/dashboard.html';
}, 1000);
}elseif(this.responseText=="error"){
document.getElementById('alertBox').innerHTML = 'Invalid login details';
document.getElementById('alertBox').className = 'alert alert-danger';
document.getElementById('alertBox').style.display = 'block'
}
}
}
xmlhttp.open("POST", "http://www.sampleee.esy.es/login.php", true);
xmlhttp.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
xmlhttp.send("username=" + username + "&" + "password=" + password);
});
And PHP code like:
if($count == 1){
echo "success";
}else{
echo "error";
}

Basically you get that error because the thing you're trying to change is not on the page when you look for it.
What you need to do is, do not write javascript with PHP. You return something like an int from php and then use that to decide what the javascript does.
You have the html on the page and just change the content inside it.
$("#loginBtn").click(function() {
var username = document.getElementById("username").value;
var password = document.getElementById("password").value;
var xmlhttp = new XMLHttpRequest();
xmlhttp.onreadystatechange = function() {
if (this.readyState == 4 && this.status == 200) {
var str = this.responseText; //you may need to trim whitespace
var alert = document.getElementById('alertBox');
if (str.trim() == 1) {
alert.innerHTML = 'Login Success!';
alert.className = 'alert alert-success';
alert.style.display = 'block';
setTimeout(function() {
window.location.href = '../html/dashboard.html';
}, 1000);
}
else {
alert.innerHTML = 'Invalid login details';
alert.className = 'alert alert-danger';
alert.style.display = 'block';
}
}
xmlhttp.open("POST", "http://www.sampleee.esy.es/login.php", true);
xmlhttp.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
xmlhttp.send("username=" + username + "&" + "password=" + password);
});
<div id="alertbox"></div>
PHP Code:
if($count == 1){
echo 1;
}
else{
echo 0;
}

Use eval like below
$("#loginBtn").click(function() {
var username = document.getElementById("username").value;
var password = document.getElementById("password").value;
var xmlhttp = new XMLHttpRequest();
xmlhttp.onreadystatechange = function () {
if (this.readyState == 4 && this.status == 200) {
var fun = eval(this.responseText);
}
}
xmlhttp.open("POST", "http://www.sampleee.esy.es/login.php", true);
xmlhttp.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
xmlhttp.send("username=" + username + "&" + "password=" + password);
});

Submit the form when on browser reload/add new tab

Just got some codes from worldofwebcraft.com for my project examination system.I only know PHP,and I actually have no idea on javascripts because our teacher hasnt taught us yet. Please help me on how do I submit the form automatically when the user reloads the page or when he/she opens a new tab.
heres the codes:
<?php if(isset($_GET['question'])){
$question = preg_replace('/[^0-9]/', "", $_GET['question']);
$next = $question + 1;
$prev = $question - 1; ?>
<script type="text/javascript">
function countDown(secs,elem) {
var element = document.getElementById(elem);
element.innerHTML = "You have "+secs+" seconds remaining.";
if(secs < 1) {
var xhr = new XMLHttpRequest();
var url = "userAnswers.php";
var vars = "radio=0"+"&qid="+<?php echo $question; ?>;
xhr.open("POST", url, true);
xhr.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
xhr.onreadystatechange = function() {
if(xhr.readyState == 4 && xhr.status == 200) {
alert("You did not answer the question in the allotted time. It will be marked as incorrect.");
clearTimeout(timer);
}
}
xhr.send(vars);
document.getElementById('counter_status').innerHTML = "";
document.getElementById('btnSpan').innerHTML = '<h2>Times Up!</h2>';
document.getElementById('btnSpan').innerHTML += 'Click here now';
}
secs--;
var timer = setTimeout('countDown('+secs+',"'+elem+'")',1000);
}
</script>
<script>
function getQuestion(){
var hr = new XMLHttpRequest();
hr.onreadystatechange = function(){
if (hr.readyState==4 && hr.status==200){
var response = hr.responseText.split("|");
if(response[0] == "finished"){
document.getElementById('status').innerHTML = response[1];
}
var nums = hr.responseText.split(",");
document.getElementById('question').innerHTML = nums[0];
document.getElementById('answers').innerHTML = nums[1];
document.getElementById('answers').innerHTML += nums[2];
}
}
hr.open("GET", "questions.php?question=" + <?php echo $question; ?>, true);
hr.send();
}
function x() {
var rads = document.getElementsByName("rads");
for ( var i = 0; i < rads.length; i++ ) {
if ( rads[i].checked ){
var val = rads[i].value;
return val;
}
}
}
function post_answer(){
var p = new XMLHttpRequest();
var id = document.getElementById('qid').value;
var url = "userAnswers.php";
var vars = "qid="+id+"&radio="+x();
p.open("POST", url, true);
p.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
p.onreadystatechange = function() {
if(p.readyState == 4 && p.status == 200) {
document.getElementById("status").innerHTML = '';
alert("Your answer was submitted.");
var url = 'exam.php?question=<?php echo $next; ?>';
window.location = url;
}
}
p.send(vars);
document.getElementById("status").innerHTML = "processing...";
}
</script>
<script>
window.oncontextmenu = function(){
return false;
}
document.onkeydown = function() {
if(event.keyCode == 116) {
event.returnValue = false;
event.keyCode = 0;
return false;
}
}
</script>

I would do something like :
window.onbeforeunload = function() {
post_answer();
}
If post_answer() is your "submit the form"-handler. Cannot tell exactly from the code.

jquery doesn't get loaded, if i don't reload page

This code works only if I reload/refresh page, otherwise it doesn't work, I susspect issue is, because I use Jquery + normal javascript.
I have form and there is input which uses autocomplete, but while you go trough form next, it doesn't work.
The point is that input with #SchoolName isn't on first page is on 2nd page (after showcart(); function is trigered)...
Anyone have any ideas why my jquery code doesn't load properly?
I have this code:
<script type="text/javascript" language="javascript">
function autocomplete() {
$("#SchoolName").autocomplete("ajaxFuncs.php", {
cacheLength:1,
mustMatch:1,
extraParams: {getSchoolName:1}
});
};
$(document).ready(function(){
setTimeout("autocomplete()", 500);
});
function showVal(str) {
if (str == "") {
document.getElementById("txtHint").innerHTML = "* Please type in School Name.";
return;
}
if (window.XMLHttpRequest) {// code for IE7+, Firefox, Chrome, Opera, Safari
xmlhttp = new XMLHttpRequest();
} else {// code for IE6, IE5
xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");
}
xmlhttp.onreadystatechange = function () {
if (xmlhttp.readyState == 4) {
if (xmlhttp.status == 200) { // break this into 2 statements so you can handle HTTP errors
document.getElementById("txtHint").innerHTML = xmlhttp.responseText;
} else {
document.getElementById("txtHint").innerHTML = "AJAX Error (HTTP "+xmlhttp.status+")";
}
}
}; // functions declared in this way should be followed by a semi colon, since the function declaration is actually a statement.
// encodeURIComponent() does all the escaping work for you - it is roughly analogous to PHP's urlencode()
// xmlhttp.open("GET","ajaxFuncs2.php?q="+encodeURIComponent(str),true);
xmlhttp.open("GET","ajaxFuncs2.php?q="+encodeURIComponent(str),true);
xmlhttp.send();
}
</script>
<script>
function ajax(doc)
{
doc = null;
if (window.XMLHttpRequest) {
try {
doc = new XMLHttpRequest();
}
catch(e) {
if(SBDebug)
alert("Ajax interface creation failure 1");
}
}
else if (window.ActiveXObject) {
try {
doc = new ActiveXObject("Msxml2.XMLHTTP");
}
catch(e) {
try {
doc = new ActiveXObject("Microsoft.XMLHTTP");
}
catch(e) {
if(SBDebug)
alert("Ajax interface creation failure 2");
}
}
}
return doc;
}
function postIt(params) {
var doc;
// alert("postIt: " + params);
if(params == "")
params = "nada=0";
doc = ajax(doc);
if (doc) {
var url = window.location.href;
url = url.substr(0, url.lastIndexOf("/") + 1) + "clientCartPost.php";
// alert(url);
doc.open("POST", url, false);
//Send the proper header information along with the request
doc.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
doc.setRequestHeader("Content-length", params.length);
doc.setRequestHeader("Connection", "close");
document.body.style.cursor = "wait";
doc.send(params);
document.body.style.cursor = "default";
if(doc.responseText == "timeout") {
alert("Timed out");
document.location = "index.php";
}
return doc.responseText;
}
return "Connection Failed";
}
function saveCC() {
var doc;
doc = ajax(doc);
if(params == "")
params = "nada=0";
if (doc) {
var params = "";
var eVisi = document.getElementById("visiCard");
var eCard = document.getElementById("x_card_num");
if(eVisi.value.indexOf("*") < 0)
eCard.value = eVisi.value;
for(i=0; i<document.CC.elements.length; i++) {
if(document.CC.elements[i].name == "visiCard")
continue;
params += getElemValue(document.CC.elements[i]) + "&";
}
doc.open("POST", "https://dot.precisehire.com/clientCartStoreCard.php", false);
//Send the proper header information along with the request
doc.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
doc.setRequestHeader("Content-length", params.length);
doc.setRequestHeader("Connection", "close");
document.body.style.cursor = "wait";
doc.send(params);
document.body.style.cursor = "default";
// alert(doc.responseText);
return true;
}
return false;
}
function getElemValue(item)
{
// alert("Getting: " + itemBase + itemID);
// alert(itemBase + "" + itemID);
if(item.type == "radio" || item.type == "checkbox")
{
if(!item.checked)
return "";
}
if(item.type == "select-one")
{
value = item.options[item.selectedIndex].value;
}
else
value = item.value;
return item.name + "=" + escape(value) + "&";
}
function makePie()
{
var contents = postIt("command=getProgress");
document.getElementById("step2").className = "bx2";
document.getElementById("step3").className = "bx2";
document.getElementById("step4").className = "bx2";
if(contents > 0)
document.getElementById("step2").className = "bx1";
if(contents > 1)
document.getElementById("step3").className = "bx1";
if(contents > 2)
document.getElementById("step4").className = "bx1";
}
var gbColor;
function RedIn(start)
{
var id;
if(start)
gbColor = 0;
gbColor += 32;
if(gbColor > 255)
gbColor = 255;
id = 0;
var obj = document.getElementById("red" + id);
while(obj != undefined)
{
obj.style.backgroundColor = 'rgb(255,' + gbColor + ',' + gbColor + ')';
id++;
obj = document.getElementById("red" + id);
}
if(gbColor < 255 && id > 0)
setTimeout("RedIn(0)", 100);
}
function showCart(next)
{
var ca = document.getElementById("cartArea");
var params = "";
for(i=0; i<document.clientCart.elements.length; i++)
{
param = getElemValue(document.clientCart.elements[i]);
if(param != "")
params += param + "&";
}
if(next)
params += "Next=1";
// alert(params);
ca.innerHTML = postIt(params);
makePie();
// RedIn(1);
}
function tabIfComplete(formField, maxSize, nextField, e)
{
if(window.event) // IE
{
keynum = e.keyCode;
}
else if(e.which) // Netscape/Firefox/Opera
{
keynum = e.which;
}
if(keynum < 48)
return;
if(formField.value.length >= maxSize)
{
var nf = document.getElementById(nextField);
if(nf)
nf.focus();
}
}
function sendCommand(command)
{
var ca = document.getElementById("cartArea");
var params = "command=" + command;
var submitOrder = command.indexOf('submitOrder') >= 0;
// alert(command);
if(submitOrder)
{
if(document.getElementById("RESULT").checked)
{
params += "&postSettlement=result";
/*
n = postIt(params);
alert(nOID);
if(nOID > 0)
document.location="orderreview.php?id=" + nOID;
return;
*/
}
else if(document.getElementById("REPORT").checked)
{
params += "&postSettlement=report";
}
else if(document.getElementById("DUPEORDER").checked)
{
params += "&postSettlement=dupeorder";
}
postIt(params);
document.location="cart.php";
return;
}
else if(command.indexOf('priorSearches') >= 0)
{
document.location="orderreview.php?ssnlist=1";
}
else if(command.indexOf('addState') >= 0)
{
for(i=0; i<document.clientCart.elements.length; i++)
{
if(document.clientCart.elements[i].name != "Next")
params += "&" + getElemValue(document.clientCart.elements[i]);
}
}
ca.innerHTML = postIt(params);
makePie();
}
function doReset()
{
var ca = document.getElementById("cartArea");
ca.innerHTML = "";
ca.innerHTML = postIt("reset=1");
makePie();
}
function dupeOrder()
{
var ca = document.getElementById("cartArea");
ca.innerHTML = "";
ca.innerHTML = postIt("dupeOrder=1");
makePie();
}
function resetCart()
{
if(confirm("Empty current cart and start over? Are you Sure?"))
doReset();
}
function saveCart()
{
var ca = document.getElementById("cartArea");
var params = "";
for(i=0; i<document.clientCart.elements.length; i++)
{
params += getElemValue(document.clientCart.elements[i]) + "&";
}
params += "saveExit=1";
ca.innerHTML = postIt(params);
makePie();
RedIn(1);
}
function deleteOrderItem(command)
{
if(!confirm("Delete this search? Are you Sure?"))
return;
var ca = document.getElementById("cartArea");
var params = "command=" + command;
ca.innerHTML = postIt(params);
makePie();
}
// alert("Reloaded");
setTimeout("showCart();", 100);
</script>

Try to move the last line:
setTimeout("showCart();", 100);
...into the $.ready-function:
$(document).ready(function(){
setTimeout("autocomplete()", 500);
});
Otherwise it may happen that showCart() gets called before the elements you access in showCart() are known.

First: Combining jQuery + regular javascript is not a problem -- jquery is made of regular javascript.
Secondly, when you're passing a method into your callback param anything, you can usually just write the name of the method:
$(document).ready(function(){
setTimeout(autocomplete, 500);
});
Third, the issue of using XMLHttpRequest while also using jquery. Jquery has a version of the XHR that is even more cross browser compliant than that is, you should use it:
$.ajax()
Finally, please add an include to the actual jquery file at the beginning of your code..
<script type="text/javascript" src="jquery.js"></script>

Sorry to say, while formatting your code its really pain to do.
I have seen some of issue right now:-
function autocomplete() { first this function has improver closing }; with semi-colon
Below is the repeatitive code:-
//Send the proper header information along with the request
doc.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
doc.setRequestHeader("Content-length", params.length);
doc.setRequestHeader("Connection", "close");
document.body.style.cursor = "wait";
doc.send(params);
document.body.style.cursor = "default";</li>
This you can make into a single function call by passing proper parameters.
3.If you are using JQuery then XMLHttpRequest is not required
4.Yet to update...

Open up a javascript console (Ctrl-Shift-J) in Firefox/Chrome and look in the menu bar for other browsers and see what errors show up