I've been trying to solve this problem for hours, using tutorials from autocad site, to no avail.
What I'm trying to accomplish is very simple. I have made a block that's a single horizontal line. I've assigned a parameter point at the bottom end of the line, and a stretch action so that when the parameter point moves, the line will stretch along the point. However, IT ALWAYS MOVES. It never stretches. I can't figure out what I'm missing.