set_selected()

The method is used to select/deselect a row on the client. It takes a single Boolean argument, specifying whether the items should be selected or not.

Example:

            function GridCreated() {
                var masterTable = $find("<%=RadGrid1.ClientID%>").get_masterTableView();
                var dataItem = masterTable.get_dataItems()[0];
                dataItem.set_selected(true);
            }