External page opened in same window

Not sure if this is the right place for this but thought I'd try. I have a product page with a link that says options. What I want is that when the "options" link is pressed I want an external page that would be relativly small to open infront of the product page but in the same window with the product page ghosted out, much like many websites do with a photo slide show. Any direction or ideas is greatly appreciated. Thanks