the form's top and left location (properties window and in code) are the screen location, so you can get the screen location of the right with the left+width and bottom with the top+height of the form
the thing is that you'd have to keep track of the base form location, the dockable form's location, which direction it's moveing, and which edge to edge are touching
ie if the dackable form is moveing away from the base you dont want it to re-dock @ 10pixels (or what distance you want it to, winamp docks @ 10pixels) but you do want it to dock when moveing towards the base form.
I was thinking about doing something like this about 3 months ago, but my problem is that in vb when the frmDocking.Location event fires that's where you do all the checking for the docking, but when you have it dock, i dont know how to force a mouse button release