public int compareColumnValues(int columnIndex, boolean sortDescending,
			Object obj1, Object obj2) {
		int result = 0;

		DataColumn column = getColumn(columnIndex);
		if (column == null)
			return result;

		if (obj1 != null && obj2 != null && !obj1.equals(obj2)) {
			switch (column.getDataType()) {
				case DataColumn.DATA_TEXT :
					result = obj1.toString().compareTo(obj2.toString());
				case DataColumn.DATA_NUMERIC :
					// TODO
					break;
				case DataColumn.DATA_DATE :
					// TODO
					break;
			}
		}

		if (sortDescending) {
			return -1 * result;
		} else {
			return result;
		}
	}