private void btUpdate_Click(object sender, EventArgs e)
 {
     ChangePwd cp = new ChangePwd();
     cp.rm = this;
     this.Hide();
     cp.ShowDialog();
 }
        private void btUpdate_Click(object sender, EventArgs e)
        {
            ChangePwd cp = new ChangePwd();

            cp.rm = this;
            this.Hide();
            cp.ShowDialog();
        }