HEP PLEASE - Cannot get out of Full Screen App!!!!!

I am really hoping someone here can help me!

I connect to my Mac Mini from my iMac via screen sharing.

I have acidentally pressed the Full Screen button on teh Screen Sharing window and now I cannot find out how to get out of it, on a normal App I just hit Esc and I am back to normal window but this is not working in Screen Sharing, I guess because the Esc key is being passed to the Shared Screen.

How in **** do I get out of this!!!!!!!!

Robin