var object = false;

    if (window.XMLHttpRequest) object = new XMLHttpRequest();
    else if (window.ActiveXObject) object = new ActiveXObject("Microsoft.XMLHTTP");
         
    function getData(dataSource, divID)
    {
       object.onreadystatechange = function()
            {
                if (object.readyState == 4)
                   document.getElementById(divID).innerHTML= object.responseText;
            }
            object.open("GET", dataSource,true);
       object.send(null);
    }

    function Dynamic_Filtr_on()
    {
          getData('dynamic.php?akcja=filtr_on','DynamicDiv');
    }

    function Dynamic_Filtr_off()
    {
          getData('dynamic.php?akcja=filtr_off','DynamicDiv');
    }