Electric window problem

[Edy]

Help please
The drivers electric window go's down no problem but when its going up the front end of the window(nearest the bonnet) drops down causing the rear of the window 2 slip forward out of the gap it runs up along in the door

I can't seem to see why. I removed the door card and seen there was anonther channel towards the front of th door that the window has to run through amd it wasn't.
So thinking I had solved the problem I routed the window in through this runner and still didn't solve the problem.
On further investigation I seen that the rear side of the window near the top corner had a clip missing compared to the passenger. I presumed mayb dat kept it running up along there tightly. So I got sum metal made it same size and bounded it to the window. Still no luck
The bottom of the window has a lip on it towards the back that connect it to the motor
Should there be another near the front or why is my window falling forward constantly?

[Grant]

There should be a black plastic tab on the 'back' side of the window. Check this is present and lined correctly with rear window seal.