int h, w;
//w = System.Windows.Forms.Screen.GetWorkingArea(this).Width;
//h = System.Windows.Forms.Screen.GetWorkingArea(this).Height;
h = System.Windows.Forms.Screen.PrimaryScreen.Bounds.Height;
w = System.Windows.Forms.Screen.PrimaryScreen.Bounds.Width;
gt.FormBorderStyle = FormBorderStyle.None;
gt.Size = new Size(w, h);
gt.ShowData(_mur);
gt.ShowDialog();