You're missing a semi-colon after the first line:
var target = $("#targetSelectBox")//;
Be sure that this selector is actually finding your element:
<select id="targetSelectBox">
<!-- options to come -->
</select>
We'll also need to see the full portion of your code, including what values
is to begin with. Additionally, make sure that jQuery is properly referenced, and you might even consider wrapper your inner target
reference in the jQuery wrapper as well:
var newOption = $("<option>").val( parts[0] ).text( parts[1] );
$(target).append(newOption);
Functional example online: http://jsbin.com/ibeci/edit