Jquery OnChange触发但没有返回数据

Question

I have posted this a few times looking for some help, I cant seem to work out why i dont get any data from my dynamic drop down but i do from the 2 static fields. I did get some answers but mainly saying that i need to sort out the security, which i hope to learn next before anything is live online, everything looks good in Firebug including the trace for the http request, i think its a problem with the query i am trying to run, i will post this again and see if anyone can help me out before i address the security flaws.

Thanks alot for helping me out.

first is html, the subcategory is the problem, all items are stored in a javascript array and works fine, just not the query

<select name="Category" id="Category" 
onchange="javascript: dropdownlist(this.options[this.selectedIndex].value);">
<option value="">Select Category</option>

<select name="subcategory" id="subcategory">
<option value="">Select Sub-Category</option>
</select>

<script>

$(function() {
  $('#subcategory').change(function() {
        $('#subcategory').load('results.php', {value: $(this).val()});
  });
});

</script>

 $category=$_POST['Category'];
 $subcategory=$_POST['Subcategory'];
 $destination=$_POST['Destination'];


 $result = mysql_query("SELECT * FROM travel WHERE Category='$category' 
 AND Subcategory='$subcategory' AND Destination='$destination'")
 or die(mysql_error());


 $row = mysql_fetch_assoc( $result ) ;

echo to table (not posted as is working ok)

Answer 1

Where to even start? Your field name is 'subcategory'. You pass 'value' to results.php and you're attempting to retrieve 'Subcategory' form the $_POST array. You need to line all these names up.

I'm not sure whether the PHP there is the code for results.php or for whatever script the form is posted to, or are they the same? Regardless, whatever results.php needs, you need to include in the data you pass to load. For example, since you currently use 'value', you'd retrieve that via $_POST['value'], not $_POST['Subcategory'].