Very loose Vostro 1500 Screen

Hi guys, I have a Vostro 1500 that's been used for a few years now. The screen has been moved up/down so many times that it's extremely loose. I'm not sure how to exactly tighten the screen from moving back and forth really easily. I've taken it apart and attempted to tighten the brackets, but I'm not sure how. Any suggestions? Thanks!

I've tried tightening these:
http://forum.notebookreview.com/attachment.php?attachmentid=13595&d=1199012929

but there's not a way to tighten them as far as I know (On the Vostro).

 

What usually gets loose are the small screws on the hinge base plate so that the screen has play from front to back.

 

Yeah, That's what came loose. I tightened them and the screen is much better. It's not as firm as I wish it was, but it's a lot better than it was which is good enough for me. Thanks!