private void retrait_Click(object sender, EventArgs e)
 {
     opType = TypesOperation.RETRAIT.ToString();
     opForm = new OperationForm(opType);
     opForm.ShowDialog();
 }
 private void depot_Click(object sender, EventArgs e)
 {
     opType = TypesOperation.DEPOT.ToString();
     opForm = new OperationForm(opType);
     opForm.ShowDialog();
 }