creating a pop up with div tag

Hello, I have this simple div tag that I want to pop up. This site has a simple script:

http://www.javascripttoolbox.com/lib/popup/example.php

I'm using the "Simple Popup Using In-Page DIV" example.

I was wondering if anyone can help me figure out what the javascript code is to make the Popup.show() function work?

I'm new to php/javascript and need help

Also, if you can, can you help me make the pop up dragable and have a close link?

Thank you

 

view page source might help you understand ....
for dragable div try this
http://www.dynamicdrive.com/dynamicindex4/image3.htm

 

I was looking at the source code, and I saw a popup.js script they had. It was super long, is there a shorter script that I might be able to get?

I'm new to coding. Thanks

Edit: I made a div tag and a javascript code where if a user clicks more, it shows more from my list. But how do i make it pop out of the screen without the window page.

<script type="text/javascript">
  function pop(div)
{
document.getElementById(div).style.display='block';
return false
}
function hide(div)
{
document.getElementById(div).style.display='none';
return false
}</script>

<a href="#" onclick="return pop('pop1');">more...</a>

<a href="#" onClick="return hide('pop1')">Close</a>

PHP: