How to make a pop up bubble

Hey, I've been trying to figure out how to make a pop up message appear where the mouse is when the user hovers over a specific area of the webpage, I don't know if this would be CSS or JavaScript but either way it would be great if I could get this worked out by 11:00 am Thursday. Thanks for the support! ^_^

Its called "Javascript onMouseover"
It simply executes a javascript when you move your mouse over the link/script.

FOR HTML>

Code:
<element onmouseover="SomeJavaScriptCode">

FOR JAVASCRIPT>

Code:
object.onmouseover=function(){SomeJavaScriptCode};

Example:

Code:
<img onmouseover="bigImg(this)" src="smiley.gif" alt="Smiley">

Source: W3Schools