Changing Content Backgrounds

[kelly923]

I'm using Joomla 2.5 with the default beez 20 template, so far I've manage to make a few small changes , but I want to add an image behind the content area.
I've searched the CSS in position.css , personal.css but I can only add one image for all the pages by using this below in the personal.css file

/* ### contentarea ### */

#contentarea,
#contentarea2
{
background:#ffffff url(../images/content3.png) no-repeat;

}

I'd like to be able to have different contentarea backgrounds for different pages
and also make the content area 100% wide

Can you please help me ?

Thank you for your time.