AJAX script customization

We would like to use AJAX autocompleter from [login to view URL] ([login to view URL]) and to use it in our site’s search bar at http://www.ecomvia.com. We’ve already been using this, but the problem is, that it doesn’t meet our requirements in full range. What we actually need: You can see it working at [login to view URL] in searching panel. The problem is, that when you are typing in search string field, the script automatically suggests the search string, BUT when user hits Enter, the site will search the first result suggested by script, NOT the string typed by user. Well I mean, that the site should search the string from the autocompleter suggest, ONLY when the user select it with keyboard’s arrows, but primary it should be searching, what the user has typed. Please let me know, if you would be able to work this out for you and then we can negotiate another conditions.