Develop Reference

html Input type number with Thousand Separator

i want to add thousand separator on keyup event in input type number
but this work just in 6 character, if more than 6 character, value on input has reseted
this my short code
<input type="number" id="tanpa-rupiah" step="any">
var dengan_rupiah = document.getElementById('dengan-rupiah');
dengan_rupiah.addEventListener('keyup', function(e)
{
dengan_rupiah.value = formatRupiah(this.value, 'Rp. ');
});
function formatRupiah(bilangan, prefix)
{
var number_string = bilangan.replace(/[^,\d]/g, '').toString(),
split = number_string.split(','),
sisa = split[0].length % 3,
rupiah = split[0].substr(0, sisa),
ribuan = split[0].substr(sisa).match(/\d{1,3}/gi);
if (ribuan) {
separator = sisa ? '.' : '';
rupiah += separator + ribuan.join('.');
}
rupiah = split[1] != undefined ? rupiah + ',' + split[1] : rupiah;
return prefix == undefined ? rupiah : (rupiah ? 'Rp. ' + rupiah : '');
}
this my fiddle https://jsfiddle.net/C2heg/4619/

This might suit you. On keydown prevent the default action if it is not a number key. On keyup, parse the value and update it. Use the data- attributes to store and get the original value.
var elem = document.getElementById("num");
elem.addEventListener("keydown",function(event){
var key = event.which;
if((key<48 || key>57) && key != 8) event.preventDefault();
});
elem.addEventListener("keyup",function(event){
var value = this.value.replace(/,/g,"");
this.dataset.currentValue=parseInt(value);
var caret = value.length-1;
while((caret-3)>-1)
{
caret -= 3;
value = value.split('');
value.splice(caret+1,0,",");
value = value.join('');
}
this.value = value;
});
function showValue()
{
console.log(document.getElementById("num").dataset.currentValue);
}
<input type="text" id="num" maxlength="30">
<button onclick="showValue()">Get Value</button>

Ok I have posted answer below. I have added limit of 20 numbers. You can change it as per your need.
You can use Number.toLocaleString() for this purpose.
Below is working example:
// When ready.
$(function() {
var extra = 0;
var $input = $("#amount");
$input.on("keyup", function(event) {
// When user select text in the document, also abort.
var selection = window.getSelection().toString();
if (selection !== '') {
return;
}
// When the arrow keys are pressed, abort.
if ($.inArray(event.keyCode, [38, 40, 37, 39]) !== -1) {
if (event.keyCode == 38) {
extra = 1000;
} else if (event.keyCode == 40) {
extra = -1000;
} else {
return;
}
}
var $this = $(this);
// Get the value.
var input = $this.val();
var input = input.replace(/[\D\s\._\-]+/g, "");
input = input ? parseInt(input, 10) : 0;
input += extra;
extra = 0;
$this.val(function() {
return (input === 0) ? "" : input.toLocaleString("en-US");
});
});
});
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<input id="amount" name="amount" type="text" maxlength="20" />

change your the input type equal to "text" then its work
<input type="text" id="tanpa-rupiah" step="any">
checkout jsfiddle

How do you prevent bad user input on watched input fields in angular?

I have a watched input field on a grid with pagination. Something like X of 28 Pages.
I want the user to be able to change that input, but I also want to prevent bad input.
My checks are >= 1 or <= Max Pages (28 in this case). The input defaults to 1.
I accomplished this by comparing the new value against those constraints, if it fails, revert to the old value. The problem comes when someone wants to type in 20 lets say. This requires they delete the 1, and type 20. As soon as they delete 1, it fails the constraints and reverts back to 1 making impossible to type in 20.
Is there anyway to accomplish this without removing it from the $watch?

You could use a combination of <input type="number"> and your own directive that has a parser and a listener for the blur event. That way your watch will only get executed when the page number is a valid page, or once with null when the input is invalid, but the user can input whatever until the blur event fires. Something like this:
<!doctype html>
<html ng-app="myApp">
<head>
<script src="http://code.jquery.com/jquery-1.9.1.min.js"></script>
<script src="http://code.angularjs.org/1.0.5/angular.min.js"></script>
<script>
angular.module('myApp', []).controller('Ctrl', function($scope) {
$scope.pageNumber = 1;
})
.directive('myPagenumber', function() {
return {
require: 'ngModel',
link: function($scope, elem, attrs, ctrl) {
$scope.$watch(attrs.ngModel, function(val) {
console.log('ng-model value: ' + val);
});
var parsePage = function(val) {
var num = parseInt(val, 10);
if (isNaN(num)) {
return null;
} else if (num > 28 || num < 1) {
return 1;
} else {
return num;
}
}
ctrl.$parsers.push(function(val) {
return parsePage(val);
});
elem.bind('blur', function() {
var page = parsePage(elem.val());
if (page === null)
page = 1;
$scope.$apply(function() {
ctrl.$setViewValue(page);
ctrl.$render();
});
});
}
};
});
</script>
</head>
<body ng-controller="Ctrl">
<input type="number" ng-model="pageNumber" my-pagenumber>
</body>
</html>

I wrote an example for you:
var min = 1;
var max = 28;
$('.page').live('keydown', function (e){
var currentVal = $(this).val();
//enter,tab, shift
if(e.which == 37 || e.which == 39 || e.which == 9 || e.which == 8) {
return;
// key up
} else if(e.which == 38){
if(currentVal < max){
currentVal++;
}
$(this).val(currentVal);
//key down
} else if( e.which == 40) {
if(currentVal > min){
currentVal--;
}
$(this).val(currentVal);
//only numbers
} else if(e.which >= 48 && e.which <= 57){
var val = e.which - 48;
if(e.target.selectionEnd == e.target.selectionStart) {
val = currentVal.insert(e.target.selectionEnd, val);
} else {
val = currentVal.replace(currentVal.substr(getSelectionStart(e.target),getSelectionEnd(e.target)),val);
}
if(min<=val && val <= max) {
$(this).val(val);
}
}
e.preventDefault();
});
// utility functions
//get the start index of the user selection
function getSelectionStart(o) {
if ( typeof o.selectionStart != 'undefined' )
return o.selectionStart;
// IE And FF Support
o.focus();
var range = o.createTextRange();
range.moveToBookmark(document.selection.createRange().getBookmark());
range.moveEnd('character', o.value.length);
return o.value.length - range.text.length;
};
//get the end index of the user selection
function getSelectionEnd(o) {
if ( typeof o.selectionEnd != 'undefined' )
return o.selectionEnd;
// IE And FF Support
o.focus();
var range = o.createTextRange();
range.moveToBookmark(document.selection.createRange().getBookmark());
range.moveStart('character', - o.value.length);
return range.text.length;
};
/*
* Insert Text at a index
*/
String.prototype.insert = function (index, string) {
if (index > 0)
return this.substring(0, index) + string + this.substring(index, this.length);
else
return string + this;
};
animate example: http://jsfiddle.net/PVxqe/1/

Jquery keydown() with number format not work correctly on android webview

I have encountered a strange behavior on android browser / webview. I was testing an input that will automatically format to phone number format "(xxx) xxx-xxxx". But then what happened was when I tapped or press any number on androids keyboard, the first input was like this "(x" but then the cursor was in between "(" and "x". Is there a way to put the cursor after "x" value?
I tested this on iPhone and windows web browsers and it works fine. Please let me know if there are mistakes on my jquery or javascripts.
Thanks
HTML CODE:
<html>
<head>
<title>Sample Phone Number Format</title>
<script type="text/javascript" src="http://code.jquery.com/jquery-1.8.2.min.js"></script>
</head>
<body>
<input type="text" id="phone" />
<script type="text/javascript">
$('#phone').on('keydown', function (event) {
objval = $(this).val();
if (event.keyCode == 46 || event.keyCode == 8) {} else {
if (!((event.keyCode > 47 && event.keyCode < 58) || (event.keyCode > 95 && event.keyCode < 106) || (objval.length > 13))) {
event.preventDefault();
} else {
if (objval.length == 0) {
$(this).val(objval + '(');
alert(objval + '(');
} else if (objval.length == 4) {
$(this).val(objval + ') ');
alert(objval + ') ');
} else if (objval.length == 9) {
$(this).val(objval + '-');
alert(objval + '-');
} else if (objval.length >= 14) {
if (event.keyCode == 9) {
return;
} else {
event.preventDefault();
}
}
}
}
});
$('#phone').on('keydown', function (event) {
var objVal = $(this).val();
if(objVal.length < 14)
{
validateCallerForm(objVal + String.fromCharCode((96 <= event.keyCode && event.keyCode <= 105)? event.keyCode-48 : event.keyCode));
}
});
//Validates proper phone format, true if valid phone number, false otherwise
function isValidPhoneNumber(elementValue) {
var numberPattern = /^\(?(\d{3})\)?[- ]?(\d{3})[- ]?(\d{4})$/;
return numberPattern.test(elementValue);
}
//validates entire caller form, also updates css classes for proper response
function validateCallerForm(PhoneNumber) {
if (isValidPhoneNumber(PhoneNumber)) {
alert("true");
} else {
alert("false");
}
}
</script>
</body>
</html>
Giving +50 Bounty to who'm will answer this correctly

you have to first define listener for typing and copy-paste like below (not required) :
$("#phone").keyup( function() {
maskLine(this);
});
$("#phone").change( function() {
maskLine(this);
});
Then, to manage cursor placement, you have to cache previous phone number and then, you could compare difference and update cursor position if needed.
So declare, you have to declare a global array like this :
var _cacheElementValues = new Array();
At last, you can check the function below, it applies your mask to phone number field and manage cursor placement :
function maskLine( element ) {
element = $(element);
var maskedLine = '';
var line = element.attr('value');
// check the cache of the input and abord if no change since last treatment
if (_cacheElementValues[element.attr('id')] != undefined && _cacheElementValues[element.attr('id')] == line) {
return;
}
line = line.replace(/\D/g, ''); // remove all characters != digits
line = line.substring(0, 10);
if (line != '') {
// apply mask
if (line.length <= 2 ) {
maskedLine = "(" + line;
} else if (line.length < 6) {
maskedLine = line.replace(/^([0-9]{3})([0-9]{0,3})/g, '($1) $2');
} else {
// mask : '(XXX) XXX-XXXX'
maskedLine = line.replace(/^([0-9]{3})([0-9]{3})([0-9]{0,4})/g, '($1) $2-$3');
}
}
// define cursor position at the end of the input by default
var pos = maskedLine.length;
// Change cursor placement if necessary
if (typeof element[0].selectionStart != 'undefined') {
var start = element[0].selectionStart;
var end = element[0].selectionEnd;
var insText = element[0].value.substring(start, end);
// get current cursor placement
if (insText.length == 0) {
pos = start;
} else {
pos = start + insText.length;
}
// find how many digits typing since last mask application
var previousLength = 0;
if (_cacheElementValues[element.attr('id')] != undefined) {
previousLength = _cacheElementValues[element.attr('id')].replace(/\s/g, '').length;
}
var diff = maskedLine.replace(/\s/g, '').length - previousLength;
// if sum of new typing digit is > 0 : we change cursor placement
if (diff > 0) {
pos += (diff - 1) + Math.round((diff-1)/3);
if (pos%6 == 0 && maskedLine.length >= pos+1) pos++;
}
}
// update input data & cache
element.val(maskedLine);
_cacheElementValues[element.attr('id')] = maskedLine;
// update cursor placement
element[0].selectionStart = element[0].selectionEnd = pos;
}
You can find this example on jsFiddle : http://jsfiddle.net/UE9LB/5/
I hope this little explantion can solve your problem ;)
Enjoy !
ps: i apologize for my poor english :s

I'd recommend at least starting with an existing plugin rather than going through your own isolated rounds of solving issues.
http://digitalbush.com/projects/masked-input-plugin/
https://github.com/igorescobar/jQuery-Mask-Plugin

The short answer is to set the selectionStart and selectionEnd properties of the input element. After you format the value, set these properties to this.value.length.
this.selectionStart = this.value.length;
this.selectionEnd = this.value.length;
But, where you are going to run into trouble is when the cursor is not at the end of the text. Eg, the user has manually positioned the cursor to a position within the text. To prevent the cursor from jumping to the end, you will need to detect the cursor position before you format the input, then put the cursor back in the appropriate position after formatting.
Edit: This jsFiddle may get you started, but isn't perfect yet.

I rewrite the code on my #phone keydown event and this will work on iPhone, Android, webkit browsers.
$('#phone').on('keydown', function (event) {
if (event.keyCode == 8 || event.keyCode == 37 || event.keyCode == 39) {
// ignore if BKSPCE, left arrow, or right arrow
} else {
// validate if anything else
inputval = $(this).val();
var string = inputval.replace(/[^0-9]/g, "");
var first3 = string.substring(0,3);
var next3 = string.substring(3,6);
var next4 = string.substring(6,10);
var string = ("(" + first3 + ") " + next3 + "-" + next4);
$(this).val(string);
}
});

Phone mask with jQuery and Masked Input Plugin

I have a problem masking a phone input with jQuery and Masked Input Plugin.
There are 2 possible formats:
(XX)XXXX-XXXX
(XX)XXXXX-XXXX
Is there any way to mask it accepting both cases?
EDIT:
I tried:
$("#phone").mask("(99) 9999-9999");
$("#telf1").mask("(99) 9999*-9999");
$("#telf1").mask("(99) 9999?-9999");
But it doesn't works as I would like.
The closest one was (xx)xxxx-xxxxx.
I would like to get (xx)xxxx-xxxx when I type the 10th number, and (xx)xxxxx-xxxx when I type the 11th. Is it posible?

Try this - http://jsfiddle.net/dKRGE/3/
$("#phone").mask("(99) 9999?9-9999");
$("#phone").on("blur", function() {
var last = $(this).val().substr( $(this).val().indexOf("-") + 1 );
if( last.length == 3 ) {
var move = $(this).val().substr( $(this).val().indexOf("-") - 1, 1 );
var lastfour = move + last;
var first = $(this).val().substr( 0, 9 );
$(this).val( first + '-' + lastfour );
}
});

Here is a jQuery phone number mask. No plugin required.
Format can be adjusted to your needs.
Updated JSFiddle.
HTML
<form id="example-form" name="my-form">
<input id="phone-number" name="phone-number" type="text" placeholder="(XXX) XXX-XXXX">
</form>
JavaScript
$('#phone-number', '#example-form')
.keydown(function (e) {
var key = e.which || e.charCode || e.keyCode || 0;
$phone = $(this);
// Don't let them remove the starting '('
if ($phone.val().length === 1 && (key === 8 || key === 46)) {
$phone.val('(');
return false;
}
// Reset if they highlight and type over first char.
else if ($phone.val().charAt(0) !== '(') {
$phone.val('('+$phone.val());
}
// Auto-format- do not expose the mask as the user begins to type
if (key !== 8 && key !== 9) {
if ($phone.val().length === 4) {
$phone.val($phone.val() + ')');
}
if ($phone.val().length === 5) {
$phone.val($phone.val() + ' ');
}
if ($phone.val().length === 9) {
$phone.val($phone.val() + '-');
}
}
// Allow numeric (and tab, backspace, delete) keys only
return (key == 8 ||
key == 9 ||
key == 46 ||
(key >= 48 && key <= 57) ||
(key >= 96 && key <= 105));
})
.bind('focus click', function () {
$phone = $(this);
if ($phone.val().length === 0) {
$phone.val('(');
}
else {
var val = $phone.val();
$phone.val('').val(val); // Ensure cursor remains at the end
}
})
.blur(function () {
$phone = $(this);
if ($phone.val() === '(') {
$phone.val('');
}
});

Actually the correct answer is on http://jsfiddle.net/HDakN/
Zoltan answer will allow user entry "(99) 9999" and then leave the field incomplete
$("#phone").mask("(99) 9999-9999?9");
$("#phone").on("blur", function() {
var last = $(this).val().substr( $(this).val().indexOf("-") + 1 );
if( last.length == 5 ) {
var move = $(this).val().substr( $(this).val().indexOf("-") + 1, 1 );
var lastfour = last.substr(1,4);
var first = $(this).val().substr( 0, 9 );
$(this).val( first + move + '-' + lastfour );
}
});​

You need a jQuery plugin for the mask works as well.
-- HTML --
<input type="text" id="phone" placeholder="(99) 9999-9999">
<input type="text" id="telf1" placeholder="(99) 9999*-9999">
<input type="text" id="telf2" placeholder="(99) 9999?-9999">
-- JAVASCRIPT --
<script src="https://raw.githubusercontent.com/igorescobar/jQuery-Mask-Plugin/master/src/jquery.mask.js"></script>
<script>
$(document).ready(function($){
$("#phone").mask("(99) 9999-9999");
$("#telf1").mask("(99) 9999*-9999");
$("#telf2").mask("(99) 9999?-9999");
});
</script>

You can use the phone alias with Inputmask v3
$('#phone').inputmask({ alias: "phone", "clearIncomplete": true });
$(function() {
$('input[type="tel"]').inputmask({ alias: "phone", "clearIncomplete": true });
});
<label for="phone">Phone</label>
<input name="phone" type="tel">
<script src="https://code.jquery.com/jquery-2.2.4.min.js"></script>
<script src="https://cdn.jsdelivr.net/gh/RobinHerbots/Inputmask#3.3.7/dist/inputmask/inputmask.js"></script>
<script src="https://cdn.jsdelivr.net/gh/RobinHerbots/Inputmask#3.3.7/dist/inputmask/inputmask.extensions.js"></script>
<script src="https://cdn.jsdelivr.net/gh/RobinHerbots/Inputmask#3.3.7/dist/inputmask/inputmask.numeric.extensions.js"></script>
<script src="https://cdn.jsdelivr.net/gh/RobinHerbots/Inputmask#3.3.7/dist/inputmask/inputmask.date.extensions.js"></script>
<script src="https://cdn.jsdelivr.net/gh/RobinHerbots/Inputmask#3.3.7/dist/inputmask/inputmask.phone.extensions.js"></script>
<script src="https://cdn.jsdelivr.net/gh/RobinHerbots/Inputmask#3.3.7/dist/inputmask/jquery.inputmask.js"></script>
<script src="https://cdn.jsdelivr.net/gh/RobinHerbots/Inputmask#3.3.7/dist/inputmask/phone-codes/phone.js"></script>
https://github.com/RobinHerbots/Inputmask#aliases

Using jQuery Mask Plugin there is two possible ways to implement it:
1- Following Anatel's recomendations:
https://gist.github.com/3724610/5003f97804ea1e62a3182e21c3b0d3ae3b657dd9
2- Or without following Anatel's recomendations:
https://gist.github.com/igorescobar/5327820
All examples above was coded using jQuery Mask Plugin and it can be downloaded at:
http://igorescobar.github.io/jQuery-Mask-Plugin/

var $phone = $("#input_id");
var maskOptions = {onKeyPress: function(phone) {
var masks = ['(00) 0000-0000', '(00) 00000-0000'];
mask = phone.match(/^\([0-9]{2}\) 9/g)
? masks[1]
: masks[0];
$phone.mask(mask, this);
}};
$phone.mask('(00) 0000-0000', maskOptions);

With jquery.mask.js
http://jsfiddle.net/brynner/f9kd0aes/
HTML
<input type="text" class="phone" maxlength="15" value="85999998888">
<input type="text" class="phone" maxlength="15" value="8533334444">
JS
// Function
function phoneMask(e){
var s=e.val();
var s=s.replace(/[_\W]+/g,'');
var n=s.length;
if(n<11){var m='(00) 0000-00000';}else{var m='(00) 00000-00000';}
$(e).mask(m);
}
// Type
$('body').on('keyup','.phone',function(){
phoneMask($(this));
});
// On load
$('.phone').keyup();
Only jQuery
http://jsfiddle.net/brynner/6vbrqe6z/
HTML
<p class="phone">85999998888</p>
<p class="phone">8599998888</p>
jQuery
$('.phone').text(function(i, text) {
var n = (text.length)-6;
if(n==4){var p=n;}else{var p=5;}
var regex = new RegExp('(\\d{2})(\\d{'+p+'})(\\d{4})');
var text = text.replace(regex, "($1) $2-$3");
return text;
});

The best way to do this is using the change event like this:
$("#phone")
.mask("(99) 9999?9-9999")
.on("change", function() {
var last = $(this).val().substr( $(this).val().indexOf("-") + 1 );
if( last.length == 3 ) {
var move = $(this).val().substr( $(this).val().indexOf("-") - 1, 1 );
var lastfour = move + last;
var first = $(this).val().substr( 0, 9 ); // Change 9 to 8 if you prefer mask without space: (99)9999?9-9999
$(this).val( first + '-' + lastfour );
}
})
.change(); // Trigger the event change to adjust the mask when the value comes setted. Useful on edit forms.

The best way to do it on blur is:
function formatPhone(obj) {
if (obj.value != "")
{
var numbers = obj.value.replace(/\D/g, ''),
char = {0:'(',3:') ',6:' - '};
obj.value = '';
upto = numbers.length;
if(numbers.length < 10)
{
upto = numbers.length;
}
else
{
upto = 10;
}
for (var i = 0; i < upto; i++) {
obj.value += (char[i]||'') + numbers[i];
}
}
}

As alternative
function FormatPhone(tt,e){
//console.log(e.which);
var t = $(tt);
var v1 = t.val();
var k = e.which;
if(k!=8 && v1.length===18){
e.preventDefault();
}
var q = String.fromCharCode((96 <= k && k <= 105)? k-48 : k);
if (((e.shiftKey || (e.keyCode < 48 || e.keyCode > 57)) && (e.keyCode < 96 || e.keyCode > 105)) && e.keyCode!=46 && e.keyCode!=37 && e.keyCode!=8 && e.keyCode!=39) {
e.preventDefault();
}
else{
setTimeout(function(){
var v = t.val();
var l = v.length;
//console.log(l);
if(k!=8){
if(l<4){
t.val('+7 ');
}
else if(l===4){
if(isNaN(q)){
t.val('+7 (');
}
else{
t.val('+7 ('+q);
}
}
else if(l===7){
t.val(v+')');
}
else if(l===9){
t.val(v1+' '+q);
}
else if(l===13||l===16){
t.val(v1+'-'+q);
}
else if(l>18){
v=v.substr(0,18);
t.val(v);
}
}
else{
if(l<4){
t.val('+7 ');
}
}
},100);
}
}

I was developed simple and easy masks on input field to US phone format jquery-input-mask-phone-number
Simple Add jquery-input-mask-phone-number plugin in to your HTML file and call usPhoneFormat method.
$(document).ready(function () {
$('#yourphone').usPhoneFormat({
format: '(xxx) xxx-xxxx',
});
});
Working JSFiddle Link https://jsfiddle.net/1kbat1nb/
NPM Reference URL https://www.npmjs.com/package/jquery-input-mask-phone-number
GitHub Reference URL https://github.com/rajaramtt/jquery-input-mask-phone-number

If you don't want to show your mask as placeholder you should use jQuery Mask Plugin.
The cleanest way:
var options = {
onKeyPress: function(phone, e, field, options) {
var masks = ['(00) 0000-00000', '(00) 00000-0000'];
var mask = (phone.length>14) ? masks[1] : masks[0];
$('.phone-input').mask(mask, options);
}
};
$('.phone-input').mask('(00) 0000-00000', options);

Yes use this
$("#phone").inputmask({"mask": "(99) 9999 - 9999"});
Link here

$('.phone').focus(function(e) {
// add mask
$('.phone')
.mask("(99) 99999999?9")
.focusin(function(event)
{
$(this).unmask();
$(this).mask("(99) 99999999?9");
})
.focusout(function(event)
{
var phone, element;
element = $(this);
phone = element.val().replace(/\D/g, '');
element.unmask();
if (phone.length > 10) {
element.mask("(99) 99999-999?9");
} else {
element.mask("(99) 9999-9999?9");
}
}
);
});

How to limit the number of characters entered in a text area

Here's my attempt at limiting the number of characters entered into a text area:
var limit = 255;
var txt = $('textarea[id$=txtPurpose]');
$(txt).keyup(function() {
var len = $(this).val().length;
if (len > limit) {
//this.value = this.value.substring(0, 50);
$(this).addClass('goRed');
$('#spn').text(len - limit + " characters exceeded");
return false;
} else {
$(this).removeClass('goRed');
$('#spn').text(limit - len + " characters left");
}
});
However, it doesn't work very well. How can I prevent a user from entering text once a certain limit has been reached, say 255 characters?

Though this question is pretty old. If I was you I do something very simple like
<textarea maxlength="255"></textarea>
This would limit the users to enter only 255 characters in the textarea.

Here's what I use to limit something to 1200 chars. When someone types too many characters, I just truncate the contents of that textarea.
$(function() {
//set up text length counter
$('#id_limited_textarea').keyup(function() {
update_chars_left(1200, $('#id_limited_textarea')[0], $('#text_chars_left'));
});
//and fire it on doc ready, too
update_chars_left(1200, $('#id_limited_textarea')[0], $('#text_chars_left'));
});
function update_chars_left(max_len, target_input, display_element) {
var text_len = target_input.value.length;
if (text_len >= max_len) {
target_input.value = target_input.value.substring(0, max_len); // truncate
display_element.html("0");
} else {
display_element.html(max_len - text_len);
}
}

$(this).val( $(this).val().substring(0, limit) );

To simplify this to the bare bone basic:
<textarea name="message" onkeydown="return this.value.substr(0,160)"></textarea>
Set your max to where 160 is.

My plugin:
(function($) {
$.fn.textCounter = function(options) {
var defaults = {
maxlimit: 100, // max limit character
description: null, // element for descript count character
enter: true // if accept enter
};
var options = $.extend({}, defaults, options);
if (options.description != null) {
if (typeof options.description == 'string')
options.description = $('#' + options.description);
}
var fevent = function(ev) {
var value = $(this).val(),
k = ev.charCode || ev.keyCode || ev.which,
incremente = 1;
if (k == 8)
incremente = -1;
if (options.enter == false && k == 13)
return false;
if (ev.ctrlKey || ev.altKey || ev.metaKey) //Ignore
return true;
if ((value.length + incremente) > options.maxlimit)
return false;
return true;
};
var fcounter = function(ev) {
var value = $(this).val();
$(options.description).text(options.maxlimit - value.length);
};
$(this).each(function(i, el) {
if ($(this).is(':input')) {
$(this).unbind('keypress.textCounter').bind('keypress.textCounter', fevent);
$(this).unbind('keyup.textCounter').bind('keyup.textCounter', fcounter);
}
});
};
})(jQuery);

var limit="NO of characters";<br><br>
$(this).val( $(this).val().substring(0, limit) );