window.parent.document.all.NowClickID.value 为空或不是对象

Question

<script language="javascript" type="text/javascript">
    var NowOrderNo = <%=OrderNo%> * 2 - 1;
    var NowCount = <%=NowCount%>;
    var NowClickID;
    function TableOnMouseOver(xname)
    {
        NowClickID = window.parent.document.all.NowClickID.value;
        if ((NowClickID != xname) )
        {
            document.all[xname].className = "style_0_menu_ctable_on";
        }
    }
    function TableOnMouseOut(xname)
    {
        NowClickID = window.parent.document.all.NowClickID.value;
        
        if ((NowClickID != xname) )
        {
            document.all[xname].className = "style_0_menu_ctable_off";
        }
    }
    function TableOnClick(xname,linkname)
    {
        
        window.parent.document.all.NowClickID.value = xname;
        for(x=1;x<=NowCount;x++)
        {
        //alert(x);
            menuname = "x" + x;
            if (NowClickID != menuname)
            {
                document.all[menuname].className = "style_0_menu_ctable_off";
            }
        }  
        window.parent.parent.mainFrame.location.href = linkname;
    AllResetCondition();
    document.all[xname].className = "style_0_menu_ctable_click";
    }
    
    function ResetCondition()
    {
        for(x=1;x<=NowCount;x++)
        {
          menuname = "x" + x;
    document.all[menuname].className = "style_0_menu_ctable_off";
        }
    }
    
    function AllResetCondition()
    {
        var NowWindowRowsValue = window.parent.switchrows.rows;
    var RowsArray = NowWindowRowsValue.split(",");
    //alert(NowWindowRowsValue);
    //alert(RowsArray.length);
        for (xx=0;xx<RowsArray.length;xx++)
        {
            if (xx%2==1)
            {
                window.parent.frames(xx).ResetCondition();
            }
        }
    } 
</script>
出错代码为上,请高手帮忙!!