Basic Ajax Program

<script language="Javascript">
function xmlhttpPost(strURL) {
var xmlHttpReq = false;
var self = this;
// Mozilla/Safari
if (window.XMLHttpRequest) {
self.xmlHttpReq = new XMLHttpRequest();
}
// IE
else if (window.ActiveXObject) {
self.xmlHttpReq = new ActiveXObject("Microsoft.XMLHTTP");
}
self.xmlHttpReq.open('POST', strURL, true);
self.xmlHttpReq.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');
self.xmlHttpReq.onreadystatechange = function() {
if (self.xmlHttpReq.readyState == 4) {
updatepage(self.xmlHttpReq.responseText);
}
}
self.xmlHttpReq.send(getquerystring());
}

function getquerystring() {
var form = document.forms['f1'];
var word = form.word.value;
qstr = 'w=' + escape(word); // NOTE: no '?' before querystring
return qstr;
}

function updatepage(str){
document.getElementById("result").innerHTML = str;
}
</script>