private void onlineToolStripMenuItem_Click(object sender, EventArgs e)
 {
     if (dict == null)
     {
         dict             = new OnlineDict();
         dict.MdiParent   = this;
         dict.FormClosed += new FormClosedEventHandler(Dict_Close);
         dict.Show();
     }
     else
     {
         dict.Activate();
     }
     dict.WindowState = FormWindowState.Maximized;
 }
 private void Dict_Close(object sender, FormClosedEventArgs e)
 {
     dict = null;
 }