public void FillProductCombo() { try { BusinessManager BM = new BusinessManager(); cmbProductName.AutoCompleteSource = AutoCompleteSource.ListItems; //cmbProductName.DropDownStyle = ComboBoxStyle.DropDownList; cmbProductName.DisplayMember = "ProductName"; cmbProductName.DataSource = BM.BALFillProductCombo().Tables[0]; } catch (Exception ex) { MessageBox.Show(ex.Message, "Error", MessageBoxButtons.OK, MessageBoxIcon.Error); } }