To get Grid View Rows in Javascript

<script language="javascript" type="text/javascript">

var gridViewCtlId = '<%=ctlGridView.ClientID%>';
    var gridViewCtl = null;
    var curSelRow = null;
    var curRowIdx = -1;
    function getGridViewControl()
    {
        if (null == gridViewCtl)
        {
            gridViewCtl = document.getElementById(gridViewCtlId);
        }
    }
    
    function onGridViewRowSelected(rowIdx)
    {
        var selRow = getSelectedRow(rowIdx);
        if (null != selRow)
        {
            curSelRow = selRow;
            var cellValue = getCellValue(rowIdx, 0);
            alert(cellValue);
        }
    }
    
    function getSelectedRow(rowIdx)
    {
        return getGridRow(rowIdx);
    }
    
    function getGridRow(rowIdx)
    {
        getGridViewControl();
        if (null != gridViewCtl)
        {
            return gridViewCtl.rows[rowIdx];
        }
        return null;
    }
    
    function getGridColumn(rowIdx, colIdx)
    {
        var gridRow = getGridRow(rowIdx);
        if (null != gridRow)
        {
            return gridRow.cells[colIdx];
        }
        return null;
    }
    
    function getCellValue(rowIdx, colIdx)
    {
        var gridCell = getGridColumn(rowIdx, colIdx);
        if (null != gridCell)
        {
            return gridCell.innerText;
        }
        return null;
    }
</script>