Okay, I managed to make it much faster, this verion is really fast.

And that means GetRowByKeyValue is super slow!

///

///

///

function UnCheckRows(gridID) {

    try {

        var grid        = ISGetObject(gridID);

        var table       = grid.RootTable;

        var checkedRows = table.GetCheckedRows();

        var nLenght     = checkedRows.length;

        for (var i = 0; i < nLenght; i++) {

            var row = table.ToRowObject(checkedRows[i]);

            row.Uncheck();

        }

    }

    catch (err) {

        alert("UnCheckRows: " + err.description);

    }

}

Hello Maged,

Yes, you're right Maged. We have several ways to get the row object. some of this several options is using ToRowObject  and GetRowByKeyValue, but if we compare both of them, ToRowObject method more useful to get the row object than GetRowByKeyValue method, just like your experiment.

Regards.
Riendy