Amy,
Control.Refresh - does an Control.Invalidate followed by Control.Update.
Control.Invalidate - invalidates a specific region of the Control (defaults
to
entire client area) and causes a paint message to be sent to the control.
Control.Update - causes the Paint event to occur immediately (Windows will
normally
wait until there are no other messages for the window to process, before
raising the Paint event).
The paint event of course is where all the drawing of your form occurs. Note
there is only one pending Paint event, if you call Invalidate 3 times, you
will still only receive one Paint event.
Hope this helps
Jay