Please help,

The window application by default allows more than one application instance to run at the same time,
What shuold i do (MFC) in order to allow only one instance of my window application to run at one time?
Can somebody pass the code to me if this is easy to be done?

2) I want to display a status saying "work in progress..please wait" as my GUI and at the same time,
my program is running behind and get the work done..., how can i do this? do i need multithreading to do this in MFC?

Thanks!!