jqueryajax检索php get变量

我想从ajax表单（input.php）中获取$id变量，并使其在主页上可用，这样我就可以在action='ask.php？q='中使用此变量提交（）表单

主页：

<script type='text/javascript'>
$(document).ready(function(){

$('#questionSubmit').click(function(){

    $.post("input.php", { question: questionForm.question.value , detail: questionForm.detail.value }, );

});

});

</script>
<form method='POST' action='ask.php?q=<?php echo $id ?>' name='questionForm'>   
        <p>Question:</p>
        <p><input type='text' name='question' id='question'></p>

        <p><textarea id='detail' name='detail'></textarea></p>
        <p>Tags:</p>
        <p><input type='button' value='submit' name='questionSubmit' id='questionSubmit'></p>
    </form>

$（文档）.ready（函数（）{
$（“#问题提交”）。单击（函数（）{
$.post（“input.php”，{question:questionForm.question.value，detail:questionForm.detail.value}，）；
});
});
<?php
include '../connect.php';
    if (isset($_POST['questionSubmit'])){

    $question=mysql_real_escape_string($_POST['question']);
    $detail=mysql_real_escape_string($_POST['detail']);
    $date=date("d M Y");
    $time=time();
    $user=$_SESSION['id'];
    $put=mysql_query("INSERT INTO questions VALUES ('','$question','$detail','$date','$time','$user','subject','0')");

    $result=mysql_query("SELECT * FROM questions WHERE user='$user' AND time='$time'");
        while ($row = mysql_fetch_assoc($result)){

             $id=$row['id'];

            }

    }
?>


$.post("input.php", { question: questionForm.question.value , detail: questionForm.detail.value },
   function(data) {
    //add the id to question input, or any other input element you want
     $("#question").val(data);
   });

//and your input.php, echo the $id
while ($row = mysql_fetch_assoc($result)){

             $id=$row['id'];

            }
echo $id;