AJAX Basics

for Other browsers except IE

objXmlHttp=new XMLHttpRequest();

for > IE 6.0

objXmlHttp=new ActiveXObject("Msxml2.XMLHTTP");

others

objXmlHttp=new ActiveXObject("Microsoft.XMLHTTP");

0 The request is not initialized
1 The request has been set up
2 The request has been sent
3 The request is in process
4 The request is complete

xmlhttp.onreadystatechange=function_name
xmlhttp.open("GET",url,true);
xmlhttp.send(null);