private void btn_Modify_Click(object sender, EventArgs e)
{
Global.umode = "MODIFY";
studentdetails stud_det = new studentdetails();
stud_det.Show();
}
private void btn_Add_Click(object sender, EventArgs e)
{
Global.umode = "ADD";
studentdetails stud_det = new studentdetails();
stud_det.Show();
}