1991 240 What attaches window to regulator?

[s10lowrider1994]

The passenger window on my 240 is wigging out and I'm trying to figure out what I need to fix it. The regulator works fine, the window simply isn't attached at the bottom like it's supposed to be. I see the channel but don't see anywhere clamps would be like on most cars, it's just a channel. The window will roll up and down, it just has a tendency to come loose on the down swing and releases itself from the channel so I've gotta push it down manually. Basically the channel it sits in pulls itself away from the window when I roll the window down. Are there clamps that are missing? Is it just held in there with glue or pressure? I'm not sure what to look for as the PO has butchered everything possible so I can't tell for sure what is rom isn't supposed to be there in regards to the window mechanism. The car has almost 500 thousand miles so I'm sure something is either worn out, missing or broken, I just don't know what it is. Any ideas?