private void btDecrypt_Click(object sender, EventArgs e)
 {
     try
     {
         using (MySqlBackup mb = new MySqlBackup())
         {
             mb.DecryptDumpFile(txtSource.Text, txtOutput.Text, txtPwd.Text);
         }
         MessageBox.Show("Done");
     }
     catch (Exception ex)
     {
         MessageBox.Show(ex.Message);
     }
 }