为什么它从ajax插入空字符串

Question

add_data={"name":$("#name").val(), "smst":$("#smst option:selected").val(), "grade":$("#grade option:selected").val(), "score":$("#score option:selected").val(), "label":$("#label option:selected").val()};

        $.ajax({
            url: "add.php",
            type: "POST",
            data: add_data,
            contentType: 'charset=EUC-KR',
            dataType: "text",
            success: function(data){
                alert(data);
            },

it's ajax.

mysql_select_db("a");
$name=$_POST['name'];
$smst=$_POST['smst'];
$grade=$_POST['grade'];
$score=$_POST['score'];
$label=$_POST['label'];
$query="insert into calcul VALUES ('$name', '$smst','$grade','$score','$label');";
mysql_query($query);

it's php mysql

and when ajax excute, insert nothing to DB... someone help me! X(

Answer 1

Set contentType to 'application/x-www-form-urlencoded; charset=UTF-8' or remove it completely, because this is default value.