Autosizing image for infobox border

[Guest]

I am hoping someone can help me here.

 

I have been going through my CSS references and cannot find the answer. Am starting to think that this is not possible.

 

I have a .gif image that I want to use as a border in the infoboxes.

 

As these boxes vary in size I would like to have the image to resize to 100% of the box.

 

Have tried various methods to no avail.

 

Is it possible to do this in the stylesheet file, or will I have to add code to the various box files.

 

Thanks for your time.