popup contact form

A client of mine wants to do a contact form popup similar to this website http://www.dentalcorp.ca/. If you go to that site and go to any page and click on the contact link from top, The page will pop up taking up the entire screen. but if you look at the url of the website what you will notice is that it is not going to a contact page. Meaning you don’t see a /contact or a contact link like that.

I was able to do that popup similar to that website as you can see from my clients website here http://allaboutmac.ca/new/ but mine is still going to a contact page. As a result I had to put some kind of thank you message in the contact page.

my question is how do I completely hide the contact page so the users will see the contact form in popup similar to this website http://www.dentalcorp.ca/. Can anyone please help.