private void menuWnd_Popup(object sender, EventArgs e)
{
// These menus require an MDIChild in order to work
bool bEnable = this.MdiChildren.Length > 0 ? true : false;
cascadeToolStripMenuItem.Enabled = bEnable;
tileToolStripMenuItem.Enabled = bEnable;
closeAllToolStripMenuItem.Enabled = bEnable;
}