<!-- Hide me from old browsers
var xmlHttp, timerID;

function search_now(str)
{
    if (str.length < 3) return;
    
    xmlHttp=GetXmlHttpObject();
    if (xmlHttp==null)
    {
        getByID("ajax-loader").style.display = "none";
        return;
    }    
    var url=root_url + "search.php?keywords="+str+"&page=products&rand="+Math.random();
    if (typeof sess_params!='undefined')
    {
        url=url+"&"+sess_params;
    }
    if (timerID)
    {
        clearTimeout(timerID);
    }
    timerID = setTimeout("requestData('"+url+"')",500);
    //requestData(url);
} 

function requestData(url)
{
    xmlHttp.onreadystatechange=stateChanged;
    xmlHttp.open("GET",url,true);
    xmlHttp.send(null); 
}

function stateChanged() 
{ 
    if (xmlHttp.readyState==4)
    { 
        getByID("dynamic-zone").innerHTML=xmlHttp.responseText;
        getByID("ajax-loader").style.display = "none";
        filterFix();
    }
    else
    {
    	getByID("ajax-loader").style.display = "inline";
    }
}
<!-- stop hiding -->