Hi Libby;
1) FYI .. you would use an ArrangeSheets (Layer!) method on the DashBoard "sheet" in order to maximize it into the MDI frame. Just prior to that, you would need to perform a SetFocus ( ) on the sheet to make sure its the target of the ArrangeSheets( ) method.
2) To control the "auto-restore" of the DashBoard sheet on the MDI frame - I would suggest that each sheet send an event to the MDI frame that signifies a sheet closing (ie: on the CLOSE event). The MDI Frame could use a GetNextSheet ( ) method in a loop to count the active sheets and if the only one found was the DashBoard - then use the command I suggested in #1 to maximize it.
3) FYI .. when a Sheet minimizes - it is always visible as an icon along the lower section of the MDI Frame. So when you say "invisible" to you mean completely?
Regards ... Chris