为什么我无法获得ajax值？

i try to send some data to my php file from ajax , but i could not succeed. This is my ajax file,

 var artistIds = new Array();

    $(".p16 input:checked").each(function(){
        artistIds.push($(this).attr('id'));
    });


    $.post('/json/crewonly/deleteDataAjax2',artistIds,function(response){
        if(response == 'ok')
            alert('error');
        else
            alert('nop');
    })

and in PHP side i use this code

 extract($_POST);

 if(isset($artistIds))
     $this->sendJSONResponse('ok');
 else
     $this->sendJSONResponse('error');

$artistIds always come with null why why why

finally i came to this but also does not work

    var artistIds = new Array();

    $(".p16 input:checked").each(function(){
        artistIds.push($(this).attr('id'));
    });


   $.post('/json/crewonly/deleteDataAjax2', { artistIds: artistIds },function(response){
        if(response == 'ok')
            alert('dolu');
        elseif (response == 'error')
            alert('bos');
    });*

You can't post an array without serializing into name-value pairs.

See: http://api.jquery.com/serialize/

You'll need to pass an object to associate values with names.

var data = {
    artistIds: artistIds //Here, the property name is "artistIds", which is going to be the name of your PHP variable. Your JS variable is also called that.
};

$.post('/json/crewonly/deleteDataAjax2',data,function(response){
//...

Do your $.post like this:

$.post('/json/crewonly/deleteDataAjax2', { artistIds: artistIds }, ...);