Help with HTML forms.?

Hi. I'm drawing a blank here... I'm trying to make a simple html document, which contains a single text box and a submit button. The user types any URL they wish into the box, then when they click submit, it simply opens this page: a href="http://api.dot.tk/tweak/shorten?long=xyz" rel="nofollow"http://api.dot.tk/tweak/shorten?long=xyz/a with xyz being the URL the person types into the box. Better yet, how can I make it copy the first line of the returned page and display it in nice big letters? Thanks. I don't usually write HTML but this is a bit interesting.