public TeacherAllocationViewModel AddAndUpdateTeacherAllocation(TeacherAllocationViewModel vmModel)
 {
     try
     {
         if (vmModel.ID > 0)
         {
             var record = _db.TeacherAllocations.OrderByDescending(x => x.ID).Where(x => x.ID == vmModel.ID).FirstOrDefault();
             record.ClassMasterID   = vmModel.ClassMasterID;
             record.TeacherMasterID = vmModel.TeacherMasterID;
             record.StudentMasterID = vmModel.StudentMasterID;
             _db.SaveChanges();
         }
         else
         {
             TeacherAllocation _TeacherAllocation = new TeacherAllocation();
             _TeacherAllocation.ClassMasterID   = vmModel.ClassMasterID;
             _TeacherAllocation.TeacherMasterID = vmModel.TeacherMasterID;
             _TeacherAllocation.StudentMasterID = vmModel.StudentMasterID;
             _db.TeacherAllocations.Add(_TeacherAllocation);
             _db.SaveChanges();
             vmModel.ID = _TeacherAllocation.ID;
         }
     }
     catch (Exception ex)
     {
     }
     return(vmModel);
 }
        protected void Submit_Click(object sender, EventArgs e)
        {
            TeacherAllocationViewModel vmModel = new TeacherAllocationViewModel();

            vmModel.ClassMasterID   = Convert.ToInt32(ClassMasterID.Text);
            vmModel.TeacherMasterID = Convert.ToInt32(TeacherMasterID.Text);
            vmModel.StudentMasterID = Convert.ToInt32(StudentMasterID.Text);

            if (HiddenField1.Value != "")
            {
                vmModel.ID = Convert.ToInt32(HiddenField1.Value);
            }
            vmModel = iTeacherAllocationService.AddAndUpdateTeacherAllocation(vmModel);
            if (vmModel.ID > 0)
            {
                Response.Write("<script>alert('Record saved successfully')</script>");
                Response.Redirect("TeacherAllocation.aspx");
            }
            bindGrid();
        }