//Load data for ComboBox private void Load_form() { _dt = _dbDetails.GetDataTableDetailsOnUserDep(_userDep); List <string> listSort = new List <string>(); List <string> listType = new List <string>(); //set first value in combobox listSort.Add(""); listType.Add(""); foreach (DataRow row in _dt.Rows) { //check data on repeat if (!listSort.Contains(row[1])) { listSort.Add(row[1].ToString()); } if (!listType.Contains(row[2])) { listType.Add(row[2].ToString()); } } //fill comboboxes data _ctrlDetail.FillComboboxSort(listSort); _ctrlDetail.FillComboboxType(listType); }