Зависание XMLHTTP

var browserCreated = false;
var browser = CreateBrowser();
var answer = '';

if ( browser !== null ) browserCreated = true;

function CreateBrowser()
{
if ( typeof XMLHttpRequest != "undefined")
{
return new XMLHttpRequest;
} else if(window.ActiveXObject) {
var http = new ActiveXObject("Microsoft.XMLHTTP");
return http;
}

}

function post(url,data)
{
browser.open('POST',url,1);
browser.setRequestHeader("Content-Type","application/x-www-form-urlencoded");
browser.onreadystatechange=returnresponse;
browser.send(data);
}

function get(url)
{
browser.open('GET',url,1);
browser.onreadystatechange=returnresponse;
browser.send(null);
}

function returnresponse()
{
alert(1)
if (browser.readyState==4){
answer = browser.responseText;
alert(answer);
}
}