changing base url

hey, my rails app is viewed in a frame of another site. My problem is that because of that all my links and redirects move my site out of the frame and present the links on their own...I'll try to explain better:

Lets say my domain is: my home page is but u should view it using: (meaning my site should be viewed only through a frame in the website) from the home page u can move with a link to a different page: lets say: link_to 'link' :action => 'show' now when u press the link the browser will go to but I want it to go to

In short I want to replace to

hope I made it clear enough... Thnx !