Create Click to highlight feature

If you use adsense when you are given your ad code it is in a scrolling window box and when you click it all the html in that box is highlighted.

How is that done?

 

http://forums.digitalpoint.com/showthread.php?t=173938

 

I see, but how do you put it all together?

I found a website that gives some instructions

codeave.com/javascript/code.asp?u_log=7004

but I dont want a button. How do you do it so that when you click the text body al the text is sellected

 

Nevermind I found it

plus2net.com/javascript_tutorial/textarea-onclick.php

 

EDIT: Too late...

<textarea onclick="this.focus(); this.select();"></textarea>

HTML: