var xmlHttp

    function Races(race_id)
    { 
        var url="../users/getraces.php?race_grp_id="+race_id;
        xmlHttp=GetXmlHttpObject(stateChangedRaces)
        xmlHttp.open("GET", url , true)
        xmlHttp.send(null)
       
    }
   
    function stateChangedRaces()
    {
        if (xmlHttp.readyState==4 || xmlHttp.readyState=="complete")
        {
             
            var result=xmlHttp.responseText;
            document.getElementById("list_races").innerHTML=result;
           
        }
    }    
    function GetXmlHttpObject(handler)
    {
        var objXmlHttp=null
   
        if (navigator.userAgent.indexOf("Opera")>=0)
        {
            alert("This example doesn't work in Opera")
            return
        }
        if (navigator.userAgent.indexOf("MSIE")>=0)
        {
            var strName="Msxml2.XMLHTTP"
            if (navigator.appVersion.indexOf("MSIE 5.5")>=0)
            {
                strName="Microsoft.XMLHTTP"
            }
            try
            {
                objXmlHttp=new ActiveXObject(strName)
                objXmlHttp.onreadystatechange=handler
                return objXmlHttp
            }
            catch(e)
            {
                alert("Error. Scripting for ActiveX might be disabled")
                return
            }
        }
            if (navigator.userAgent.indexOf("Mozilla")>=0)
            {
                objXmlHttp=new XMLHttpRequest()
                objXmlHttp.onload=handler
                objXmlHttp.onerror=handler
                return objXmlHttp
            }
    }