//Basic Ajax Routine- Author: Dynamic Drive (http://www.dynamicdrive.com)
//Last updated: Jan 15th, 06'

function createAjaxObj(){
var httprequest=false
if (window.XMLHttpRequest){ // if Mozilla, Safari etc
httprequest=new XMLHttpRequest()
if (httprequest.overrideMimeType)
httprequest.overrideMimeType('text/xml')
}
else if (window.ActiveXObject){ // if IE
try {
httprequest=new ActiveXObject("Msxml2.XMLHTTP");
} 
catch (e){
try{
httprequest=new ActiveXObject("Microsoft.XMLHTTP");
}
catch (e){}
}
}
return httprequest
}

var ajaxpack=new Object()
ajaxpack.basedomain="http://"+window.location.hostname
ajaxpack.ajaxobj=createAjaxObj()
ajaxpack.filetype="txt"
ajaxpack.addrandomnumber=0 //Set to 1 or 0. See documentation.

ajaxpack.getAjaxRequest=function(url, parameters, callbackfunc, filetype){
ajaxpack.ajaxobj=createAjaxObj() //recreate ajax object to defeat cache problem in IE
if (ajaxpack.addrandomnumber==1) //Further defeat caching problem in IE?
var parameters=parameters+"&ajaxcachebust="+new Date().getTime()
if (this.ajaxobj){
this.filetype=filetype
this.ajaxobj.onreadystatechange=callbackfunc
this.ajaxobj.open('GET', url+"?"+parameters, true)
this.ajaxobj.send(null)
}
}

ajaxpack.postAjaxRequest=function(url, parameters, callbackfunc, filetype){
ajaxpack.ajaxobj=createAjaxObj() //recreate ajax object to defeat cache problem in IE
if (this.ajaxobj){
this.filetype=filetype
this.ajaxobj.onreadystatechange = callbackfunc;
this.ajaxobj.open('POST', url, true);
this.ajaxobj.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
this.ajaxobj.setRequestHeader("Content-length", parameters.length);
this.ajaxobj.setRequestHeader("Connection", "close");
this.ajaxobj.send(parameters);
}
}

//ACCESSIBLE VARIABLES (for use within your callback functions):
//1) ajaxpack.ajaxobj //points to the current ajax object
//2) ajaxpack.filetype //The expected file type of the external file ("txt" or "xml")
//3) ajaxpack.basedomain //The root domain executing this ajax script, taking into account the possible "www" prefix.
//4) ajaxpack.addrandomnumber //Set to 0 or 1. When set to 1, a random number will be added to the end of the query string of GET requests to bust file caching of the external file in IE. See docs for more info.

//ACCESSIBLE FUNCTIONS:
//1) ajaxpack.getAjaxRequest(url, parameters, callbackfunc, filetype)
//2) ajaxpack.postAjaxRequest(url, parameters, callbackfunc, filetype)

///////////END OF ROUTINE HERE////////////////////////


//////EXAMPLE USAGE ////////////////////////////////////////////
/* Comment begins here

//Define call back function to process returned data
function processGetPost(){
var myajax=ajaxpack.ajaxobj
var myfiletype=ajaxpack.filetype
if (myajax.readyState == 4){ //if request of file completed
if (myajax.status==200 || window.location.href.indexOf("http")==-1){ if request was successful or running script locally
if (myfiletype=="txt")
alert(myajax.responseText)
else
alert(myajax.responseXML)
}
}
}

/////1) GET Example- alert contents of any file (regular text or xml file):

ajaxpack.getAjaxRequest("example.php", "", processGetPost, "txt")
ajaxpack.getAjaxRequest("example.php", "name=George&age=27", processGetPost, "txt")
ajaxpack.getAjaxRequest("examplexml.php", "name=George&age=27", processGetPost, "xml")
ajaxpack.getAjaxRequest(ajaxpack.basedomain+"/mydir/mylist.txt", "", processGetPost, "txt")

/////2) Post Example- Post some data to a PHP script for processing, then alert posted data:

//Define function to construct the desired parameters and their values to post via Ajax
function getPostParameters(){
var namevalue=document.getElementById("namediv").innerHTML //get name value from a DIV
var agevalue=document.getElementById("myform").agefield.value //get age value from a form field
var poststr = "name=" + encodeURI(namevalue) + "&age=" + encodeURI(agevalue)
return poststr
}

var poststr=getPostParameters()

ajaxpack.postAjaxRequest("example.php", poststr, processGetPost, "txt")
ajaxpack.postAjaxRequest("examplexml.php", poststr, processGetPost, "xml")

Comment Ends here */


/*
	This is the JavaScript file for the How to Create CAPTCHA Protection using PHP and AJAX Tutorial

	You may use this code in your own projects as long as this 
	copyright is left in place.  All code is provided AS-IS.
	This code is distributed in the hope that it will be useful,
 	but WITHOUT ANY WARRANTY; without even the implied warranty of
 	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
	
	For the rest of the code visit http://www.WebCheatSheet.com
	
	Copyright 2006 WebCheatSheet.com	

*/
//Gets the browser specific XmlHttpRequest Object 
function getXmlHttpRequestObject() {
 if (window.XMLHttpRequest) {
    return new XMLHttpRequest(); //Mozilla, Safari ...
 } else if (window.ActiveXObject) {
    return new ActiveXObject("Microsoft.XMLHTTP"); //IE
 } else {
    //Display our error message
    alert("Your browser doesn't support the XmlHttpRequest object.");
 }
}

//Our XmlHttpRequest object
var receiveReq = getXmlHttpRequestObject();

//Initiate the AJAX request
function makeRequest(url, param) {
//If our readystate is either not started or finished, initiate a new request
 if (receiveReq.readyState == 4 || receiveReq.readyState == 0) {
   //Set up the connection to captcha_test.html. True sets the request to asyncronous(default) 
   receiveReq.open("POST", url, true);
   //Set the function that will be called when the XmlHttpRequest objects state changes
   receiveReq.onreadystatechange = updatePage; 

   receiveReq.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
   receiveReq.setRequestHeader("Content-length", param.length);
   receiveReq.setRequestHeader("Connection", "close");

   //Make the request
   receiveReq.send(param);
 }   
}

//Called every time our XmlHttpRequest objects state changes
function updatePage() {
 //Check if our response is ready
 if (receiveReq.readyState == 4) {
   //Set the content of the DIV element with the response text
   document.getElementById('result').innerHTML = receiveReq.responseText;
   //Get a reference to CAPTCHA image
   img = document.getElementById('imgCaptcha'); 
   //Change the image
   img.src = 'create_image.php?' + Math.random();
 }
}

//Called every time when form is perfomed
function getParam(theForm) {
 //Set the URL
 var url = 'captcha.php';
 //Set up the parameters of our AJAX call
// var postStr = theForm.txtCaptcha.name + "=" + encodeURIComponent( theForm.txtCaptcha.value ) + "&full_name=" + encodeURIComponent( theForm.full_name.value );
 var poststr = "txtCaptcha=" + encodeURIComponent(theForm.txtCaptcha.value) + "&full_name=" + encodeURIComponent(theForm.full_name.value)+ "&address=" + encodeURIComponent(theForm.address.value) + "&address=" + encodeURIComponent(theForm.address.value) +"&contactno=" + encodeURIComponent(theForm.contactno.value) + "&email=" + encodeURIComponent(theForm.email.value) + "&city=" + encodeURIComponent(theForm.city.value) + "&enquiry=" + encodeURIComponent(theForm.enquiry.value);

 //Call the function that initiate the AJAX request
 makeRequest(url,poststr);
}