How resize like this?

Hi guyz,

Go to
and see how long is the first page u se(#start)

now go in the end of that page and cick the “contact” button (

As u can see, the page become smaller in high; the white border are made in flash and it seems that they use a uniqye file flash and a unique html page.

How to resize the heigh of the page in this way? how they set the heigh of the page?