Javascript sleep() or wait()

While thinking on a solution for handling javascript "alerts" in Sahi, it suddenly occured to me that a sleep() or wait() method can be implemented in javascript with the help of a synchronous XMLHttp request to the server.
It goes like:

<script>
function sahiIsIE(){
var browser = navigator.appName;
return browser == "Microsoft Internet Explorer";
}

function sahiCreateRequestObject(){
var obj;
if(sahiIsIE()){
obj = new ActiveXObject("Microsoft.XMLHTTP");
}else{
obj = new XMLHttpRequest();
}
return obj;
}

function sahiSendToServer(url){
try{
var http = sahiCreateRequestObject();
var url = url;
http.open("GET", url, false);
http.send(null);
return http.responseText;
  }catch(ex){throw ex;}
}

function sleep(ms){
sahiSendToServer("http://localhost:9999/dyn/sleep?ms="+ms);
}

var start = new Date();
sleep(1000);
alert((new Date()) - start);

</script>

The url http://localhost:9999/dyn/sleep?ms=1000 does a Thread.sleep(1000);

Of course there is the network delay which makes the time out slightly greater than 1000 ms;

[Dec 20 2007] NOTE: This method can give you a way to invoke a sleep on the browser, but it will also kind of freeze the browser which may not be what you want. I solved this problem in a different way for Sahi. (javascript-sleep-or-wait-in-sahi.html)