w3schools    w3Schools
Search W3Schools :
   
HOME HTML CSS XML JAVASCRIPT ASP PHP SQL MORE...   References Examples Forum About
ADVERTISEMENTS

XML Certification
Download XML editor
Custom Programming
 
Table of contents
AJAX Basic
AJAX HOME
AJAX Intro
AJAX HTTP Request
AJAX Example
AJAX Browsers
AJAX XMLHttpRequest
AJAX Server
AJAX Server Script

AJAX Advanced
AJAX Suggest
AJAX Source
AJAX Database
AJAX XML File
AJAX ResponseXML

AJAX Examples
AJAX Examples

Selected Reading
Web Statistics
Web Glossary
Web Hosting
Web Quality

W3Schools Tutorials
W3Schools Forum

Helping W3Schools

 

AJAX - Request a Server

Previous Next

AJAX - Sending a Request to the Server

To send off a request to the server, we use the open() method and the send() method.

The open() method takes three arguments. The first argument defines which method to use when sending the request (GET or POST). The second argument specifies the URL of the server-side script. The third argument specifies that the request should be handled asynchronously. The send() method sends the request off to the server. If we assume that the HTML and ASP file are in the same directory, the code would be:

xmlHttp.open("GET","time.asp",true);
xmlHttp.send(null);

Now we must decide when the AJAX function should be executed. We will let the function run "behind the scenes" when the user types something in the username text field:

<form name="myForm">
Name: <input type="text"
onkeyup="ajaxFunction();" name="username" />
Time: <input type="text" name="time" />
</form>

Our updated AJAX-ready "testAjax.htm" file now looks like this:

<html>
<body>
<script type="text/javascript">
function ajaxFunction() {
var xmlHttp; try {
// Firefox, Opera 8.0+, Safari
xmlHttp=new XMLHttpRequest();
} catch (e) {
// Internet Explorer
try {
xmlHttp=new ActiveXObject("Msxml2.XMLHTTP");
} catch (e) {
try {
xmlHttp=new ActiveXObject("Microsoft.XMLHTTP");
} catch (e) {
alert("Your browser does not support AJAX!");
return false;
}
}
} xmlHttp.onreadystatechange=function() { if(xmlHttp.readyState==4) { document.myForm.time.value=xmlHttp.responseText; } } xmlHttp.open("GET","time.asp",true); xmlHttp.send(null);
}
</script>
<form name="myForm">
Name: <input type="text"
onkeyup="ajaxFunction();" name="username" />
Time: <input type="text" name="time" />
</form>
</body>
</html>

The next chapter makes our AJAX application complete with the "time.asp" script.


Previous Next


Altova® MissionKit® - Integrated suite of XML tools

The Altova MissionKit is a suite of intelligent XML tools, including:

XMLSpy® – industry-leading XML editor

  • Support for all XML-based technologies
  • Graphical editing views, powerful debuggers, code generation, & more

MapForce® – graphical data mapping tool

  • Drag-and-drop data conversion with code generation
  • Support for XML, DBs, EDI, Excel® 2007, text, Web services

StyleVision® – visual stylesheet designer

  • Drag-and-drop stylesheet design for XML & databases
  • Output to HTML, PDF, RTF, Word 2007, & more

And more…

Try before you buy with a free fully functional 30-day trial

Download today



 
WEB HOSTING
ASP.NET Web Hosting
ASP.NET
Web Hosting
$15 Domain Name
Registration
Save $20 / year!
Buy UK Domain Names
Register Domain Names
Cheap Domain Names
Cheap Web Hosting
Best Web Hosting
PHP MySQL Hosting
Top 10 Web Hosting
UK Reseller Hosting
Web Hosting
FREE Web Hosting
WEB BUILDING
Website Templates
Flash Templates
Website Builder
Internet Business Opportunity
Custom Programming
FREE Trial or Demo
Web Content Manager
Forms,Web Alerts,RSS
Download XML editor
FREE Flash Website
FREE Web Templates
EDUCATION
US Web Design Schools
HTML Certification
JavaScript Certification
XML Certification
PHP Certification
ASP Certification
Home HOME or Top of Page Validate   Validate   W3C-WAI level A conformance icon Printer Friendly  Printer Friendly

W3Schools is for training only. We do not warrant the correctness of its content. The risk from using it lies entirely with the user.
While using this site, you agree to have read and accepted our terms of use and privacy policy.
Copyright 1999-2009 by Refsnes Data. All Rights Reserved.