Adjustable background image to fit different size pages? (image attached)

[supersudsme]

I've had a good search through the threads (even the French ones!) trying to find an answer to this but no joy.

I have a background image declared in the global .css under the #page div thus:

background: url('../img/pshop_body.jpg') no-repeat;y;

Trouble is, as you can see from the pic attached - this comes up short when the left block becomes too large.

I'm thinking that this requires a bit of trickery with a repeatable -x slice of the bottom of the existing background image so that it 'expands' accordingly.

Million dollar question is - how can I do this?

Any suggestions most welcome.

Anyone who can help resolve will get a big thanks, undying gratitude and I'll make sure to tag this as resolved cos I'm sure other people must have run into this one too...