URL Forwarding & Pop-Up window

Hi Peeps,

I have built a website and I have put it on my own webspace. , It has a very long address so I want to shorten it. I have already tried to sign up with a .tk domain, and also a get.to domain. This works, but only for the intro. After the intro has been played you can enter the site by pressing a button which is linked to a pop-up window. When I type the address without the URL forwarding it works perfect. But as soon as I type in the URL forwarding address (get.to/b3site or www.b3-site.tk) the pop up doesn’t work.

The address is:
http://members.home.nl/a.kreijveldloo/b3/Intro.html

Can someone please help me with this problem? I hate this long address.