Scaling along the Z-Axis

Well, I need help again, but this time I provide you with a picture:
Somehow, those are going to connect when getting close to eachother, but it doesn’t do that to me, what can be the problem? I’ve tried to turn on/off the 3D cursor, but it doesn’t seem to work. All help appreciated!

It looks like you have a mirror modifier, the “do clipping” button will make the vertices “connect” when they approach each other (actually the do clipping button just stops them from moving further.) If do clipping is off, then the vertices will move past the centerline and the faces will interpenetrate.