private void preferencesToolStripMenuItem_Click(object sender, EventArgs e)
 {
     if (preferencesForm == null || preferencesForm.IsDisposed)
     {
         preferencesForm = new PreferencesForm();
         preferencesForm.Show();
     }
     else
     {
         preferencesForm.Focus();
     }
 }
 private void preferencesToolStripMenuItem_Click(object sender, EventArgs e)
 {
     if (preferencesForm == null || preferencesForm.IsDisposed)
     {
         preferencesForm = new PreferencesForm();
         preferencesForm.Show();
     }
     else
     {
         preferencesForm.Focus();
     }
 }