2002 F350 fender flares coming loose.

[sledwrecker]

Tonight I was washing my truck and I noticed the STOCK fender flare on my passanger side (bed) has come loose. I can pull it away from the truck a good inch if not more. Checked all the others and they are still tight. What do I need to fix this? Do they use some sort of clip or screws? I'll look tomorrow during the day but I thought I would ask on here to get a jump on things so I know what to look for. Again these are stock flares on a 2002 F350 Lariat crew/ long box.