How to control the current datasource record's field can edit?

// VAR Changed on 19 Mar 2012 at 13:02:40 by JXie7519
void THK_allowEditFieldList(FormDataSource   _tableDS,
                            boolean          _allowEdit = false)
{
    int             field;
    DictTable       dictTable;
    DictField       dictField;
    tableId         tableId = _tableDS.table();
    fieldId         fieldId,costCenter = fieldId2Ext(fieldnum(CustInvoiceTable, Dimension),2);
;

    dictTable = new DictTable(tableId);
    for (field = 1; field <= dictTable.fieldCnt(); field++)
    {
        fieldId = dictTable.fieldCnt2Id(field);
        dictField = new DictField(tableId, fieldId);
        if(!dictField.isSystem())
        {
            if(dictField.id() != costCenter)
                _tableDS.object(DictField.id()).allowEdit(_allowEdit);
        }
    }
}