if you're hard coding the movie names in those links like that couldn't you just have it update the div while it's loading the movie? you already have the function there and the data you need in it.
in your Ajax.Request you have an onSuccess parameter that has
var movieTags = transport.responseXML.getElementsByTagName
( 'movie' );
in it. is there "title" tag associated with the "movie" tag in your xml? you would just yank it out and use it if so.