ajax response -1 in wordpress theme

Question

I am using ajax in wordpress theme,but ir response -1,why? how to correct this?

function videospage(cnt)
{
    var pageno=cnt;

    jQuery.ajax({  
        type: "POST",  
        url: "<?php echo admin_url('admin-ajax.php'); ?>",  
        data: {  
            action: "myajaxpagination",  
            pageno: pageno,  
        },  
        success: function(datas){  
            alert(datas);  
        },  
        error: function(MLHttpRequest, textStatus, errorThrown){  
            alert(errorThrown);  
        }  
    });  

}

add_action('wp_ajax_myajaxpagination', 'my_action_pagination');  
function my_action_pagination()
{
    $pageno=$_REQUEST['pageno'];
    echo $pageno;
    die();
}

Answer 1

Pay attention that your ajax request will work only for logged in users. If you want to make it working for everybody, you have to add one more action wp_ajax_nopriv_myajaxpagination with the same hook:

function videospage(cnt)
{
    var pageno=cnt;

    jQuery.ajax({  
        type: "POST",  
        url: "<?php echo admin_url('admin-ajax.php'); ?>",  
        data: {  
            action: "myajaxpagination",  
            pageno: pageno,  
        },  
        success: function(datas){  
            alert(datas);  
        },  
        error: function(MLHttpRequest, textStatus, errorThrown){  
            alert(errorThrown);  
        }  
    });  

}

add_action('wp_ajax_myajaxpagination', 'my_action_pagination');  
add_action('wp_ajax_nopriv_myajaxpagination', 'my_action_pagination');
function my_action_pagination()
{
    $pageno=$_REQUEST['pageno'];
    echo $pageno;
    die();
}

Read more about AJAX in WordPress.