how to drag a...point?

[marmotte]

ok, my english is not so good, so here are 3 screenshots.

what i want to do:
look at the graphics no1, there are black and red points. i would like to be able to drag the red points with the mouse (like in the image no2) and change the actual shape: how can i do that?

also, if it's possible, how to tell the lines not to be straight, but rounded, like in image no3?







thanks for your help. my actionscript knowledge is good but not perfect, just to let you know ^^