public ActionResult UnassignCourses(string confirm_value)
 {
     if (confirm_value == "Yes")
     {
         string msg = courseAssignToTeacher.UnAssignAllCourses();
         ViewBag.Unassign = msg;
     }
     else
     {
         ViewBag.Unassign = "Cancle UnAssign Request";
     }
     return(View());
 }