jQuery Grid Plugin - jqGrid

Below is a custom formatter I have for a cell to place two checkboxes in a cell.    

function myFormatter(cellvalue,options,rowObject)
    {
        var regID="";
        if (rowObject[0] == "undefined")
        {
            regID = rowObject.regID    ;
        }
        else
        {
            regID = rowObject[0];
        }
        var approval = $('#grid').getLocalRow(options.rowId).approvalSelect;
        return '<input type="checkbox" id="checkBoxYes_'+options.rowId+'" name="yes"  value="'+ regID +'" ' + (approval=='Yes' ? 'checked="checked"' : '') + 'onclick="myFunctionYes(' + options.rowId + ')" />Yes&nbsp;&nbsp;'+
        '<input type="checkbox" id="checkBoxNo_'+options.rowId+'"  name="no" value="'+ regID +'" ' + (approval=='No' ? 'checked="checked"' : '') + 'onclick="myFunctionNo(' + options.rowId + ')" />No';
    }

I have a button to set all checkboxes to Yes in the grid.  I am looping through all of the records to set the cell value to Yes.  It only seems to set the first page boxes to Yes but no of the other pages have the value checked.  If I manually navigate to say page 2 and press the button then all of the cells are set to Yes.

function setAllToYes()
{
    var count = $('#grid').getGridParam("records");

    for (x=1; x<=count;x++)
    {
        var rowData = $('#grid').getRowData(x).approvalSelect;
        $('#grid').updateGridRows({approvalSelect:'Yes'}, x, false);
        $('#grid').setCell(x,'approvalSelect','Yes');
        $('#checkBoxYes_' + x).attr('checked',true);
        $('#checkBoxNo_' + x).attr('checked',false);
        $('#grid').saveRow(x,false,'clientArray');    
        var rowData1 = $('#grid').getLocalRow(x).approvalSelect;
        alert(x + " : " + rowData + " : " + rowData1);
        
    }