code to Modify Multiple selected rows in grid of axapta

code to Modify Multiple selected rows in grid of axapta

   TestTable  _TestTable,  
         _TestTableAux;  
   ;  
   for(_TestTable = TestTable_DS.getFirst();  
     _TestTable;  
     _TestTable = TestTable_DS.getnext())  
   {  
     ttsbegin;  
     select firstonly forupdate _TestTableAux  
       where _TestTableAux.recId = _TestTable.recId;  
     if(_TestTableAux)  
     {  
       TestTableAux.ID = "New Id";  
       TestTableAux.update();  
     }  
     ttscommit;  
   }