How to access gridview cell values on client side

In this article I will be discussing how you can use client side javascript to access values in specified row and column of GridView control without doing any post back. I have discussed in my previous articles about highlighting rows and raising click event in selected row of grid view control, ref to How to highlight gridview row when row is selected and How to raise gridview server side event

The technique to access cell values will build upon the technique that we used for highlighting rows and raising server side event. You can refer to same code from those articles to see how client side onclick event was handled for each selected row. Javascript code in those examples did not deal with cell values. But there are cases when you need to check what values you have in various cells of the grid view and make decision on client side. For example if a user enters a data in some cell but you need to validate it against value in some other cell or combination of cells, you may have been doing a post back and then doing the checks and failing user attempt if something was wrong with the data. But by using this technique you can avoid the post back. 

<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;
    }
</