moving point

I got another question. I created a polygon line but everytime I click on a point and move it, it creates another point. Its impossible for me to move the point of the line.
I will probably enabled a function but I'm unaware which function this might be.
Thx for your help

Are you talking about the default behavior? I'm running Diagram demo here and after polyline (you mean polyline, right?) is created, not extra points are added when I click the line.

Well, I click the line, and then you see all the points on the line. When clicking on the point on the line, I can normally move that point to another coordinate. The problem is that it creates then a new point which I can move. Its like adding points instead of moving the points

Do you see this behavior in the "simple" demo provided in Diagram Studio distribution? I don't see such behavior.

No, not in the simple demo. That's the reason why I find it so strange.
But its only appearing when creating a polyline programmatically
with curdatablock do begin
  diagram:= ....
Hope this helps

Can you please send me a small compilable project that reproduces the problem? Then I could quickly fix it. Please send it to our support e-mail address.