private void precipitation_btn_Click(object sender, EventArgs e)
 {
     if (precipitationForm == null)
     {
         precipitationForm             = new PrecipitationForm();
         precipitationForm.FormClosed += PrecipitationForm_FormClosed;
     }
     this.Cursor = Cursors.WaitCursor;
     precipitationForm.Show();
     this.Hide();
 }
 private void PrecipitationForm_FormClosed(object sender, FormClosedEventArgs e)
 {
     precipitationForm.FormClosed -= PrecipitationForm_FormClosed;
     precipitationForm             = null;
 }