AJAX dropdown function for ASP Page

An AJAX search box on a standard microsoft asp page that will fit in with the style of the existing page. The dropdown should function similarly to the AJAX function on [login to view URL] where a select list of up to 8-10 options is returned when the user begins keying data in the search box. When a user selects one of the drop down terms (as returned from a database etc), a form is submitted that will open a new page, replacing the initial page. (not spawing a new page). If the drop down item is not selected, then the text entered into the search box becomes the default search term and is passed to the search page. The Search Box is on the homepage of [login to view URL]