function loadXmlHttp(url, id) {
 var f = this;
 if(loadXmlHttp.xmlHttp !== null){
  f.xmlHttp = loadXmlHttp.xmlHttp();
  f.el = document.getElementById(id);
  f.xmlHttp.open("GET", url, true);
  f.xmlHttp.onreadystatechange = function(){f.stateChanged();};
  f.xmlHttp.send(null);
 }
 else alert('Your browser does not support AJAX!'); // substitute your desired request object unsupported code here
}

loadXmlHttp.xmlHttp = null; loadXmlHttp.re = /^http/.test(window.location.href);
/*@cc_on @*/ // used here and below, limits try/catch to those IE browsers that both benefit from and support it
/*@if(@_jscript_version >= 5) // prevents errors in old browsers that barf on try/catch & problems in IE if Active X disabled
try {loadXmlHttp.ie = window.ActiveXObject}catch(e){loadXmlHttp.ie = false;};
@end @*/
if (window.XMLHttpRequest && (!loadXmlHttp.ie || loadXmlHttp.re))
 loadXmlHttp.xmlHttp = function(){return new XMLHttpRequest();}; // Firefox, Opera 8.0+, Safari, others, IE 7+ when live - this is the standard method
else if (/(object)|(function)/.test(typeof createRequest))
 loadXmlHttp.xmlHttp = createRequest; // ICEBrowser, perhaps others
else {
 loadXmlHttp.xmlHttp = null;
// Internet Explorer 5 to 6, includes IE 7+ when local //
/*@if(@_jscript_version >= 5)
try{loadXmlHttp.xmlHttp = function(){return new ActiveXObject("Msxml2.XMLHTTP");};}
 catch(e){try{loadXmlHttp.xmlHttp = function(){return new ActiveXObject("Microsoft.XMLHTTP");};}catch(e){loadXmlHttp.xmlHttp = null;}}
@end @*/
}

loadXmlHttp.prototype.stateChanged = function(){
 if (this.xmlHttp.readyState == 4 && (this.xmlHttp.status == 200 || !loadXmlHttp.re))
  this.el.innerHTML = this.xmlHttp.responseText;
}