jquery post（）附加不需要的数据

Question

I'm testing the post() method of jQuery but I have a problem. I create 2 inputs in my html:

<label>box 1:</label><input type="text" name="box1" id="box1" autocomplete="off" size="20"/>
<label>box 2:</label><input type="text" name="box2" id="box2" autocomplete="off" size="20"/>

My function test()

function test(){
    var box1v = $('#box1').val();
    var box2v = $('#box2').val();
    $.post("test.php",{'box1':box1v,'box2':box2v},function(data){
        alert(data)
    });
}

and in my test.php I only do:

print_r($_POST);

the alert gives me

Array ( [box1]=>'value1',[box2]=>'value2')0

is the 0 at the end that is causing me problems because when I use $_POST[box1] it gives me value10 the same with $_POST[box2] who gives me value20

I don't know where this 0 is appending. Does anybody can explain me how to avoid this unwanted data please?