jqeury Api sortable needed

Jqeury, Ajax list order change

$(function() {jQuery( "#sortable" ).sortable({
  update: function( event, ui ) {onOrderChange(event, ui)}
});
function onOrderChange(event, ui)
{
		jQuery.ajax({ url: 'https://77prani.cz/posun_prani.php?pozice='+ui.item.index()+'&id='+ui.item.attr("id"),
         data: {action: 'test'},
         type: 'post',
         success: function(output) {
                      //Succesfully saved
                      //alert("Saved!");

jQuery( "#sortable li" ).each(function(index){
 $(this).children('span').html(index+1+"."); });
                  },
		error: function (xhr, ajaxOptions, thrownError) {
        //Error during saving
		//alert(xhr.status);
        //alert(thrownError);
      }
	});
}
});