Code for sending Ajax requests using pure JavaScript code

<Script language = "JavaScript" type = "text/JavaScript">
Function btnclick (){
VaR XMLHTTP = new activexobject ("Microsoft. XMLHTTP ");
If (! XMLHTTP ){
Alert ("An error occurred while creating the XMLHTTP object! ");
Return false;
}
XMLHTTP. Open ("Post", "getdata1.ashx? TS = "+ new date (), false); // prepare to send a POST request to the getdata1.ashx Server
// XMLHTTP is not a synchronous request by default (also recommended), that is, the open method does not return the data returned by the server as the downloadstring of WebClient. It is asynchronous because the onreadystatechange event needs to be monitored.
XMLHTTP. onreadystatechange = function (){
If (XMLHTTP. readystate = 4) {// server complete
If (XMLHTTP. State = 200) {// success if the status code is 200
Alert (XMLHTTP. responsetext); // responsetext is the text returned by the server. The returned content is displayed.
}
Else {
Alert ("ajax server return error ");
}
}
}
XMLHTTP. Send (); // The request starts to be sent.
}
</SCRIPT>