Post ajax to PHP - variable isn't being uploaded

Question

I am trying to pass a variable from my ajax to my php script. I can't see to get it to work. It keeps on giving me NULL when I do a var_dump on the variable.

JQUERY:

$(document).ready(function() {
        $('.trigger').click(function() {
                var id  = $(this).prev('.set-id').val();
                $.ajax({
                        type: "POST",
                        url: "../modules/Slide_Show/slide_show.php",
                        data: id
                });
                LinkUpload(id);
                function LinkUpload(id){
                        $("#link-upload").dialog();
                }
        });
});
</script>

PHP:

                $id = $_POST['id'];
                $query = mysql_query("SELECT * FROM xcart_slideshow_slides where slideid='$id'")or die(mysql_error());
                $sli = mysql_fetch_array($query);
                $slide_id = $sli['slideid'];
                $link = $sli['link'];
                var_dump($id);

I need the $id variable to post so I can dynamically change the dialog box when the click function is activated.

EDIT:

So I have changed some of my coding:

Jquery:

$(document).ready(function() {
        $('.trigger').click(function() {
                var id  = $(this).prev('.set-id').val();
                $.post(
                        "slide-show-link.php",
                        { id: id },
                        function(data,status){alert("Data: " + data + "\nStatus: " + status); }
                );
                // alert(id);
                LinkUpload(id);
        });
                function LinkUpload(id){
                        $("#link-upload").dialog();
                }
});

I wanted to see if the data was in fact being passed so I threw an alert in the .post. This is the error I'm getting now:

I have tried passing plain text and echoing it back on the page but it fails. It is just not passing.

Answer 1

Try this -

$.ajax({
     type: "POST",
     url: "../modules/Slide_Show/slide_show.php",
     data: { id : id }
});