private void btapplythreshold_Click(object sender, System.EventArgs e)
 {
     try
     {
         if (txtTemThresh.Text != "" && txtHumiThresh.Text != "" && txtPhoneThresh.Text != "")
         {
             Database myDatabase = new Database();
             int id = cbSelectVan.SelectedIndex + 1;
             int a = myDatabase.setTempVan(id,float.Parse(txtTemThresh.Text));
             int b = myDatabase.setHumiVan(id,float.Parse(txtHumiThresh.Text));
             int c = myDatabase.setPhoneNumber(txtPhoneThresh.Text);
             if(a == 1 && b == 1 && c == 1)
             {
                 MessageBox.Show("Save successful", "Imformation");
             }
             else
             {
                 MessageBox.Show("Not successful","Imformation");
             }
         }
         else
         {
             MessageBox.Show("Not enough imformation", "Error");
         }
     }
     catch { }
 }