private void gantiPasswordMenu_Click(object sender, EventArgs e)
 {
     if (FormGantiPass == null)
     {
         FormGantiPass             = new FormGantiPass(kodeKasir);
         FormGantiPass.FormClosed += new FormClosedEventHandler(formclose);
         FormGantiPass.ShowDialog();
     }
     else
     {
         FormGantiPass.Activate();
     }
 }
 Conn conn = new Conn(); //mengambil class conn
 void formclose(object sender, FormClosedEventArgs e)
 {
     formLogin     = null;
     FormGantiPass = null;
 }