seq             = (DataItemSequence *)_dataItemSeq;
        item            = get_dataitem_by_param_name(seq, arg_name_param);
        if (item != NULL) {
-               item->value >>= ret_val;
-               *err_flg        = PLP_OK;
+               if (item->value >>= ret_val) {
+                       *err_flg        = PLP_OK;
+               }
        }
        return ret_val;
 }
        seq             = (DataItemSequence *)_dataItemSeq;
        item            = get_dataitem_by_param_name(seq, arg_name_param);
        if (item != NULL) {
-               item->value >>= tmp;
-               ret_val =        (int)tmp;
-               *err_flg        = PLP_OK;
+               if (item->value >>= tmp) {
+                       ret_val         = (int)tmp;
+                       *err_flg        = PLP_OK;
+               }
        }
        return ret_val;
 }
        seq             = (DataItemSequence *)_dataItemSeq;
        item            = get_dataitem_by_param_name(seq, arg_name_param);
        if (item != NULL) {
-               item->value >>= ret_val;
-               *err_flg        = PLP_OK;
+               if (item->value >>= ret_val)
+                       *err_flg        = PLP_OK;
        }
        return ret_val;
 }
        seq             = (DataItemSequence *)_dataItemSeq;
        item            = get_dataitem_by_param_name(seq, arg_name_param);
        if (item != NULL) {
-               item->value >>= ret_val;
-               *err_flg        = PLP_OK;
+               if (item->value >>= ret_val)
+                       *err_flg        = PLP_OK;
        }
        return ret_val;
 }