private void btn_Save_Click(object sender, EventArgs e)
 {
     if (txt_GroupName.Text == "")
     {
         MessageBox.Show("Please Fill the Fields");
     }
     else
     {
         ProductGroup pg = new ProductGroup();
         pg.GroupName = txt_GroupName.Text;
         int ID = pg.Save();
         if (ID <= 0)
         {
             MessageBox.Show("Invalid Entry . Please try again");
         }
         else
         {
             this.Close();
         }
     }
 }