Create an "on page load" pop-up window?

Create an "on page load" pop-up window?

Hello,

Am very new to jquery but i have a little problem i want to do:

I want to create a pop-up windows that display (when website has finished loading), while the main page blurs behind the pop-up windows. something similar to those amazing jquery gallery stuff, but i want the new window to display another image or page?

any how?

truely appreciate any input.

Thanks.