void InitCreditorsCombo()
{
comboBox_creditors.AutoCompleteMode = AutoCompleteMode.SuggestAppend;
comboBox_creditors.AutoCompleteSource = AutoCompleteSource.ListItems;
List<Creditor> creditorList = LetterManager.GetCreditorList();
foreach (var item in creditorList)
{
comboBox_creditors.Items.Add(item.Alias.Trim());
}
}