跨域的页面上的Php会话传播不起作用

Question

跨越跨域网页的PHP会话传播

此登录表单旨在使用会话。它工作正常但会话不会传播 跨域的其他页面。似乎没有设置会话。任何帮助谢谢

<script type="text/javascript" src="jquery-1.9.1.js"></script>
<script type="text/javascript">
$(document).ready(function(){
    $('#username').focus(); // Focus to the username field on body loads
    $('#login').click(function(){ // Create `click` event function for login
        var username = $('#username'); // Get the username field
        var password = $('#password'); // Get the password field
        var login_result = $('.login_result'); // Get the login result div
        login_result.html('loading..'); // Set the pre-loader can be an animation
        if(username.val() == ''){ // Check the username values is empty or not
            username.focus(); // focus to the filed
            login_result.html('<span class="error">Enter the username</span>');
            return false;
        }
        if(password.val() == ''){ // Check the password values is empty or not
            password.focus();
            login_result.html('<span class="error">Enter the password</span>');
            return false;
        }
        if(username.val() != '' && password.val() != ''){ // Check the username and password values is not empty and make the ajax request
            var UrlToPass = 'action=login&username='+username.val()+'&password='+password.val();
            $.ajax({ // Send the credential values to another checker.php using Ajax in POST menthod
            type : 'POST',
            data : UrlToPass,
            url  : 'http://crossdomain.com/ajax.php',
            success: function(responseText){ // Get the result and asign to each cases
                if(responseText == 0){
                    login_result.html('<span class="error">Username or Password Incorrect!</span>');
                }
                else if(responseText == 1){
                    window.location = 'userpage.php';
                }
                else{
                    alert('Problem with sql query');
                }
            }
            });
        }
        return false;
    });
});
</script>






<?php
session_start();
include 'db.php'; 



if(isset($_POST['action']) && $_POST['action'] == 'login'){
    $username       = mysql_real_escape_string($_POST['username']);
    $password       = mysql_real_escape_string($_POST['password']); 
    $query          = mysql_query('SELECT * FROM users WHERE username = "'.$username.'" AND password = "'.$password.'" ');
    $num_rows       = mysql_num_rows($query); // Get the number of rows
    if($num_rows <= 0){ 
        echo 0;
    } else {
        $fetch = mysql_fetch_array($query);

        $_SESSION['userid']         = $fetch['id'];
        $_SESSION['username']   = $fetch['username'];
        echo 1;
    }
}
?>