Simple AJAX call - thank you w3.js - that has no dependencies so you can live without jQuery and still make calls to the server.

ajaxGet.js

function ajaxGet(url,cbStateChange,xmlData,method) {
    var rq;
    method = method||"GET";
    try{
        if(window.XMLHttpRequest)
            {rq = new XMLHttpRequest();} else
            {rq = new ActiveXObject("Microsoft.XMLHTTP");}
        ;;
    }catch(e) {return;}
    if(!rq) return;
    if(cbStateChange) rq.onreadystatechange = cbStateChange;
    rq.open(method,url,true);
    rq.send(xmlData);
}