dynamic block with radius

[mneal70]

I am trying to create a rectangle with a radius top - is there a way to make the radius change without letting the rest of the rectangle move with it? Basically - Can I lock the position of a point - keep lines parallel with each other or stay in a vertical or horizontal position?

[Anonymous]

Why not show what you've got so far?

If you post dynamic block drawing files here, please insert your block into another drawing. Don't post just the dynamic block
drawing file, because then any one interested has to save the file to their local machine and then insert it into another drawing to
be able to test it out. If you load up the drawing where the block has been inserted into, you can just open up that drawing file
and run bedit on the block.

[mneal70]

Thank you for your reply. If you can help me that would be great!