Shadow

Hello.

I am having trouble creating a soft, almost gradient drop shadow, could anyone help me out with some code tips?

I have a container that centres my page, inside that i have a DIV that acts as a frame for the site (border, background etc).

I would like the frame to have a drop shadow under the entire site, both sdies, left and right. I have tried adding a DIV underneath the frame, and placing an image (of the shadow) inside it but it does not render in any browser, can anyone help?

Thanks in advanced, James.