Assuming your server supports PHP, you could also use a PHP Session.

http://www.php.net/manual/en/reserved.variables.session.php

I've gotten lots of information here so I wanted to post a solution I discovered.

The problem: Getting JSON data from Javascript on the browser, to the server, and having PHP successfully parse it.

Environment: Javascript in a browser (Firefox) on Windows. LAMP server as remote server: PHP 5.3.2 on Ubuntu.

What works (version 1):
1) JSON is just text. Text in a certain format, but just a text string.

2) In Javascript, var str_json = JSON.stringify(myObject) gives me the JSON string.

3) I use the AJAX XMLHttpRequest object in Javascript to send data to the server:

request= new XMLHttpRequest()
request.open("POST", "JSON_Handler.php", true)
request.setRequestHeader("Content-type", "application/json")
request.send(str_json)
[... code to display response ...]

4) On the server, PHP code to read the JSON string:

$str_json = file_get_contents('php://input');

This reads the raw POST data. $str_json now contains the exact JSON string from the browser.

What works (version 2):
1) If I want to use the "application/x-www-form-urlencoded" request header, I need to create a standard POST string of "x=y&a=b[etc]" so that when PHP gets it, it can put it in the $_POST associative array. So, in Javascript in the browser:

var str_json = "json_string=" + (JSON.stringify(myObject))

PHP will now be able to populate the $_POST array when I send str_json via AJAX/XMLHttpRequest as in version 1 above.

Displaying the contents of $_POST['json_string'] will display the JSON string. Using json_decode() on the $_POST array element with the json string will correctly decode that data and put it in an array/object.

The pitfall I ran into:
Initially, I tried to send the JSON string with the header of application/x-www-form-urlencoded and then tried to immediately read it out of the $_POST array in PHP. The $_POST array was always empty. That's because it is expecting data of the form yval=xval&[rinse_and_repeat]. It found no such data, only the JSON string, and it simply threw it away. I examined the request headers, and the POST data was being sent correctly.

Similarly, if I use the application/json header, I again cannot access the sent data via the $_POST array. If you want to use the application/json content-type header, then you must access the raw POST data in PHP, via php://input, not with $_POST.

References:
1) How to access POST data in PHP: How to access POST data in PHP?
2) Details on the application/json type, with some sample objects which can be converted to JSON strings and sent to the server: http://www.ietf.org/rfc/rfc4627.txt

If this is your real server side code then...its completely insecure. You should never pass variables posted by users directly into your queries.

$query2 = "insert into booking(cust_email, cust_mobile, cust_name) values('$mail','$mobile','$name')";  

At least escape the values using "mysql_real_escape_string", or use prepared statements. And...dont use mysql anymore, use mysqli, which is almost identical to what you are using, but not deprecated soon.

Also, you are json encoding a string that doesnt need to be json encoded, its just a piece of text and not valid json code. This may be why @SimarjeetSingh Panghlia answer doesnt work for you.

instead of json_encoding that value, encode a structured array.

$response = array( "status" => true );

if(isset($_POST['type']))
    {
        if($_POST['type']=="booking"){
            $name = mysql_real_escape_string( $_POST ['Name'] ));    
            $mobile = mysql_real_escape_string($_POST ['Mob_Num']);
            $mail = mysql_real_escape_string($_POST ['Email']);               
            $query1 = "insert into customer(userName, userContactNumber, email) values('$name','$mobile','$mail')";
            $query2 = "insert into booking(cust_email, cust_mobile, cust_name) values('$mail','$mobile','$name')";          

            $result1 = mysql_query($query1);          
            $result2 = mysql_query($query2);
            $id = mysql_insert_id();

            $response["message"] = "Welcome Mr/Mrs ".$name."  Thanks for booking home services your booking id is =  ".$id;/* make sure you strip tags etc to prevent xss attack */

        }
    }
    else{
        $response["status"] = false;
        $response["message"] = "Invalid format";
    }

    echo json_encode($response);

    /* Note that you are making the query using ContentType:"application/json", */

which means you should respond using json regardless if query is successful or not. I would also recommend using a simple jQuery plugin called jStorage, that allows easy get/set of objects without having to serialize them.

$login = $json['registration']['first_name']

You have a couple of different ways to accomplish this:

• You should be able to first set the actual id and then include the Get_Users.php file like this. Notice that you should not echo out the output from Get_Users.php, instead only return the encoded json data using return json_encode($arr);:

// set the id in $_GET super global
$_GET['id'] = 1;
// include the file and catch the response
$result = include_once('Get_Users.php');

• You can also create a function that can be called from UserView.php:

// Get_Users.php
<?php
  function get_user($id) {
    // connect to and query database here
    // then return the result as json
    return json_encode($arr);
  }
?>

// In UserView.php you first include the above file and call the function
include_once('Get_Users.php');
$result = get_user(1);

• You could also use file_get_contents(). Notice that you need to make sure so that allow_url_fopen is enabled in your php.ini file for this to work:

$result = file_get_contents('http://example.com/Get_Users.php?id=1');

To enable allow_url_fopen you need to open up your loaded configuration file and set allow_url_fopen=1 and finally restart your webserver.

• You could also use curl to achieve the same result:

$ch = curl_init();
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($ch, CURLOPT_URL, 'http://example.com/Get_Users.php?id=1');
$result = curl_exec($ch);
curl_close($ch);

• An ajax request could also be made to get the result. This example uses jQuery:

$(document).ready(function() {
  $.get({
    url: 'Get_Users.php',
    data: 'id=1',
    success: function(response) {
      // response contains your json encoded data
      // in this case you **must** use echo to transfer the data from `Get_Users.php`
    }
  });
});

I did this not too long ago in PHP. Here's an example of "passing the request". (You'll need to enable PHP cURL, which is pretty standard with most installations.)

<?php
    //Get the JSON data POSTed to the page
    $request = file_get_contents('php://input');

    //Send the JSON data to the right server
    $ch = curl_init();
    curl_setopt($ch, CURLOPT_URL, "http://location_of_server.com/");
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
    curl_setopt($ch, CURLOPT_POST, 1);
    curl_setopt($ch, CURLOPT_HTTPHEADER, array("Content-Type: application/json; charset=utf-8"));
    curl_setopt($ch, CURLOPT_POSTFIELDS, $request);
    $data = curl_exec($ch);
    curl_close($ch);

    //Send the response back to the Javascript code
    echo $data;
?>

Can you not just require page2.php?

What I mean is:

page3.php  ->  AJAX request to page1.php
page1.php  ->  $request = json_decode(AJAX request from page3.php)
               require page2.php
page2.php  ->  process $request
               populate $response
page1.php  ->  echo json_encode($response)
page3.php  ->  AJAX response from page1.php

Chances are, you should get a book. This is not something that can be explained in detail in a short answer on this site.

in summary however, you can either

1) send requests to your php script by submitting a form on an html page, which will load a new page filled with whatever PHP sends back. in this case you do not need to use JSON at all as PHP would be returning a full html page.

2) you can use AJAX. AJAX is a javascript method of sending requests to the server (PHP), and getting a response without ever loading a new page. you would use AJAX to send a request to the php page, the php page would access the database and send back a response, the javascript would then take the response and do whatever it needs with it. the response data is usually formatted in a JSON format, because PHP can easily create JSON, and javascript can easily decode JSON once it receives it as a response. to make using AJAX simpler, you may want to look in to using jQuery, a javascript library which can simplify the process.