php：使用javascript时不插入组合框值

Question

i got a problem where one of two combo box value failed to insert into database, the combo boxes (named category and item) is dynamically changing (for example: when i select 'fruit' on the category box, the item box will show corresponding item such as 'apple', 'banana' and so on). the problem i got is the category box value failed to insert where as item box value inserts successfully. i'm using jquery.

here's the code snippet for the combo boxes:

Category
<select id="cat" name="cat">
</select>

Item
<select id="item" name="item">
</select>

here's the javascript:

<script>
var items = [
    {
        name:'CASEMENT WINDOWS 1.05mm',
        value:'CASEMENT WINDOWS 1.05mm',
        subitems: [
            {name: 'Section-5090', value: 'Section-5090'}, 
            {name: 'Section-5091', value: 'Section-5091'},
            {name: 'Section-5092', value: 'Section-5092'}, 
            {name: 'Section-921', value: 'Section-921'},
            {name: 'Section-6733', value: 'Section-6733'}
        ]
    }
];

$(function(){
    var temp = {};

    $.each(items, function(){
        $("<option />")
        .attr("value", this.value)
        .html(this.name)
        .appendTo("#cat");
        temp[this.value] = this.subitems;
    });

    $("#cat").change(function(){
        var value = $(this).val();
        var menu = $("#item");

        menu.empty();
        $.each(temp[value], function(){
            $("<option />")
            .attr("value", this.value)
            .html(this.name)
            .appendTo(menu);
        });
    }).change();


});
</script>

here's the submit code:

<?php
$host="localhost";
$user="root";
$pass="";
$db_name="proyek";
$tbl_name="purchase";

mysql_connect("$host", "$user", "$pass")or die("Cannot connect to SQL."); 
mysql_select_db($db_name);

$no=$_POST['no'];
$item=$_POST['item'];
$qty=$_POST['qty'];
$date=$_POST['date'];
$cat=$_POST['$cat'];

mysql_query("INSERT into purchase (item, qty, date, cat, no) VALUES ('$item', '$qty', '$date', '$cat', '$no')");
?>

help is much appreciated, thanks.

Answer 1

Remove this extraneous $:

$cat=$_POST['$cat'];
             ^