Question

Example is at http://jsfiddle.net/4RAPH/ or see below:

<select class="businessTypePullDown">
    <option value="" disabled selected>Business Type</option>
    <option value="1">General</option>
    <option value="2">Lawyer</option>
    <option value="3">Software Development</option>
    <option value="4">Auto-repair</option>
</select>

function filterPullDown () {
    alert('hello');
}

$("businessTypePullDown").change(filterPullDown);

Answer 1

Just a typo, you missed a dot:

 $(".businessTypePullDown")

Your fiddle updated: http://jsfiddle.net/4RAPH/1/