Checkbox check changed event

<script>


 function handleEvents()
    {
        $("input[title$='Non PO Payments']").change(function(){
CheckNonPO();
});
    }


function CheckNonPO()
{
      if($("input[title$='Non PO Payments']").is(':checked'))
{
$("nobr:contains('Vendor')").parent('h3').parent('td').parent('tr').show();
$("h3.ms-standardheader:contains('PO Number')").closest("tr").show();

}
else
{
$("nobr:contains('Vendor')").parent('h3').parent('td').parent('tr').hide();

}


}
_spBodyOnLoadFunctionNames.push("handleEvents");
</script>