Develop Reference

Hi everyone , I am new to jQuery and I was asked this question but I don't know how to do it

Ron recently started his carrier in developing web applications. As a part of his first project, he is assigned to create a web page using jQuery library. He created the web page and now he wants to check whether jQuery is loaded on his web page or not. For this, he wants to display a message “jQuery is loaded!!!” on his web page when the page is loaded. Help Ron to perform the task.
Does anyone know how to write a code to check if jQuery is loaded or not ?
[enter image description here][1]
This is the code of html .I want to know the jQuery code for this .Thanks in advance
[1]: https://i.stack.imgur.com/0E5mS.png

$('#msg').text('jQuery is loaded!!!');

I cannot get venobox to work on my website

So I am trying to use venobox on my website so when the user clicks on a picture, a box is opened and it will display a YouTube but I cannot get it to work please help me fix what I am doing wrong.
My code: http://hastebin.com/awuxarivoj.html
Thank you in advance

your code misses venobox's css and js, and there's no plugin initialization.
I only see two links with the class "venobox". Also, youtube links should have the data-vbtype="youtube". please read the documentation

It happens because you didn't properly linked required venobox plugin files.
Download venobox plugin and link it in your html document.
Also take care of ordering of linking the plugins

Why is my JSFiddle not working? (where to place script)

When I run this on my computer, the numbers disappear and reappear when I check the boxes, as desired. I think there was a problem with attaching the external resource script. Where do I put the link to the library?
I'm having a problem formatting the code to required embed the fiddle, but go to j-s-f-iddle and add /codergirl789/k37jqj2c/2/

There was a double quote in your url for your external script.
Like this:
"https://ajax.googleapis.com/ajax/libs/jquery/1.11.0/jquery.min.js
I've updated a fiddle with the current url:
http://jsfiddle.net/gregborbonus/k37jqj2c/4/
Also, if you need to load jQuery, just click the Javascript button (top right of the javascript console with the gear next to it) and under "Frameworks and Extensions" drop down to the jQuery version you want.

Using media.js on CI

I was still newbie at CI, currently try to make elearning just using one page,
using 2 div on the main body, left and right.
on the left I give just the title and when clicking on the title, the div on the right will show the pdf viewer using media.js from http://github.com/malsup/media/tree/master
But when I tried, the result just show on the next page in full page.
any body could help me or suggest to the right links?
Thanks

Here is a simple PDF viewer for php websites check it out :
http://flexpaper.devaldi.com/

One page layout for a PHP webpage

I want to make a one page layout for my webpage.
And I want to make that so, when i click a button in my navigation bar, it to display a div i've created for my content, but normally is hidden. Also, when i click on the logo of the page, the page goes to it's original state (without the content div showing).
I have no idea how to do this.
I guess your using Javascript and / or PHP for this?
Can you guys give me an example how to do this?
Example: http://www.basjansenmedia.nl/

When you go to themeforest, there's a separate category called One Page themes. Do have a look at it. Or, why not you Google it for yourself? Anyways, a few tutorials would be:
One Page
15 Useful HTML5 Tutorials and Examples For Beginners
Coding a CSS3 & HTML5 One-Page Website Template
Single Page Apps with AngularJS Routing and Templating

Assuming you use jquery
$('#myButton').click(function() {
$('#myNewDiv').show();
$('#myOldDiv').hide();
}
($'#logo').click(function() {
$('#myOldDiv').show();
$('#myNewDiv').hide();
}