I'm developing a site and I want to open a window from browser but it should not open in another browser window. It should be inside the same browser window overlapping the contents of that page. The other buttons and controls will be disabled until its closed.

I don't want to use showModalDialogue method of javascript which always has the title bar and close buttons.. I want something very clean. I've seen this on many other sites but don't know how to do it. you can find here an exact example of what I want http://dnn.mandeeps.com/Modules/Live...4/Default.aspx
click on any image thumbnail on this page and it will open the large image over the contents of the whole page.

Thank you very much

Best Regards