CMyDialog mydialog;
// Initialize dialog data
mydialog.membervariable1 = MyPermanentVariable1;
mydialog.membervariable2 = MyPermanentVariable2;
// Invoke the dialog box
if (mydialog.DoModal() == IDOK)
{
// retrieve the dialog data
MyPermanentVariable1 = mydialog.membervariable1;
MyPermanentVariable1 = mydialog.membervariable1;
}