Having problem with the background layout.

Hi i need some urgent help here. ive got a image as my background, and at the top i have several links.Under the registration link,  i add a registration form to the webpage which is longer then the image it goes past the bottom messing my layout up.Another problem is when i click onto the registration links and then click onto the other links on top, theres a pop up asking me to fill up the form which means i will be stuck at the same page.I have copied the code here but failed so..please help me.Thank You
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