public FRM_Car_Management()
        {
            InitializeComponent();

            if (frm == null)
            {
                frm = this;
            }
            this.dgGetAllCar.DataSource = Cmg.GET_ALL_CARS();
        }
        private void carManagmentfrmcarmanagment_Click(object sender, EventArgs e)
        {
            FRM_Car_Management formcarman = new FRM_Car_Management();

            formcarman.ShowDialog();
        }
 static void frm_FormClosed(object sender, EventArgs e)
 {
     frm = null;
 }