Get id of a checkbox? - jQuery

Hey, I am wondering how to get the id of a checkbox when it is checked.

This is what my HTML would probably look like at first:

<div class="check_filter">

    <div id="filter">
        <input type="checkbox" id="check1" /><label for="check1">Marketing</label>
        <input type="checkbox" id="check2" /><label for="check2">Automotive</label>
        <input type="checkbox" id="check3" /><label for="check3">Sports</label>
    </div>

</div><!-- End check_filter -->

I'm assuming the jQuery would look something like this:

$(document).ready(function() {    
    $(":checkbox").click(function(){
        var id = $(this).attr('id');

        $.post("index.php", { id: id });
       //return false to ensure the page doesn't refresh
       return false;
    });    
});

I'm trying to get the checked item id and then post that id in a mysql query to grab the results of the id from the database.

Thanks for any help on this.