my macbook pro screen is separating from the case, how to fix

This is amazing ! I just fixed my 2009 macbook using this glue ! Thank you SO MUCH !!

I sent my MacBook in for repair I got it back with the screen falling off. It has been falling off for 4 years now. The whole screen falls off. I just pop it back on when I close my laptop for the night. Not a good thing considering the price we paid for this computer. My issue is, I purchased the new MacBook and want to sell mine. I cant sell it with the screen falling off. It's still a great computer, I've always used a keypad protector so the keys have never been touched. Runs great. Has a 1t hard drive. I have the 2009 15 inch. How can I fix this so I can sell my laptop? I've retaped it a few times but doesn't last. Thank you!