hi guys,

is there any way to make an image of 1024x764 fit with screen size of 1152x864, 800x600 or other screen sizes?

You mean on a web page, not a physical desktop, right? Just checking...

Yes, there is a way:

http://www.cssplay.co.uk/layouts/background.html

(View source to see how it's done.)

Or even:

http://www.htmlite.com/faq022.php

(If you don't feel like analysing someone else's source code.)

Keep in mind, of course, that this method will stretch your image to the dimensions of the browser window, so if you have something that needs its aspect ratio maintained, it's going to look mighty funny (the stretchy bunny is a good example).