void ventanaOp_Disposed(object sender, EventArgs e)
{
ventanaOp = null;
}
private void menuItem5_Click(object sender, EventArgs e)
{
if (ventanaOp == null)
{
ventanaOp = new frmCambio();
//ventanaOp.Parent = this;
//ventanaOp.MdiParent = this;
//ventanaOp.StartPosition = FormStartPosition.Manual;
//ventanaOp.Left = 0;
//ventanaOp.Top = 0;
ventanaOp.Disposed += new EventHandler(ventanaOp_Disposed);
}
ventanaOp.Show();
ventanaOp.Focus();
}