private void toolStripTim_Click(object sender, EventArgs e) { frmTimPhieuNhan tim = new frmTimPhieuNhan(); Point p = PointToScreen(toolStripTim.Bounds.Location); p.X += toolStripTim.Width; p.Y += toolStripTim.Height; tim.Location = p; tim.ShowDialog(); if (tim.DialogResult == DialogResult.OK) { ctrl.TimPhieuNhan(tim.cmbTimPhieuNhan.SelectedValue.ToString()); } }