Possible Duplicate:
Convert an image to grayscale in HTML/CSS
How can I turn an colour image to a grey or black/white image like this website with CSS?
Can it be done solely on CSS or do I need JavaScript (jQuery)?
Thanks.
Edit:
Thanks for the answers guys. I notice that the trick is to make two different colour images - one is full colour and the other is b/w. I was hoping this can be done in one single image. So there is no way to do that isn't apart from the 'trick'??