2000 Pontiac Sunbird Driver side door won't close

Dont panic. Stop slamming the door. Listen carefully and we will be done with this in a few moments. Ok with the door open pull the door handle and with the door handle pulled stick a pen into the door latch and pop it open. This will fix it. What happened is usually the latch closes by accident so when you are shutting the door you are actually hitting the closed latch against the door striker, this is why it wont shut. Hope this helps