Detecting display resolution?

[basil]

Is there a way (with PhP or Java, or whatever) to detect a users display settings and then, for examle, display a different sized header image based on the display settings detected?

I have a header image that looks great at 800x600, but then at higher resolutions it only goes across teh screen part way. If I make its size 100%, then it looks stretched. What I'd like to do is be able to detect a persons browser (display) resolution and display a larger version of the same header if necessary.

Any ideas?

Thanks,
Basil

[AstroTeg]

You'll need JavaScript to do this. In fact, you should be able to have JavaScript do all the work and PHP would never know (JavaScript could determine the width and display the appropriate image). Although you'll need a "plan B" if the user has JavaScript disabled.