I wasn't suggesting you to use AJAX, I was just asking, because if you were using AJAX I'd know what'd be wrong.
Anyway, I think I'll be able to help here too. External JS files are not supposed to go between <script> tags. So try and remove there. Also, some browsers won't parse that file if you don't send the correct content-type header. It's a security thing.
Remove the <script> tags and add this line to the very top of your page: