Dynamic "noneSelectedText" for multiselect jquery box

I'm trying to get a dynamic field for a multiselect checkbox section of a page - specifically the noneSelectedText. Here is the html:

<select name="set_town[]" class="my_select set_town" multiple="multiple" data-selected-text="Select Town">

I found jQuery UI MultiSelect Widget - noneSelectedText for more than one select tag , but I can't get the included code sample to work. I've used both .data() and .attr() to no avail. The following works, but the "Select Town" content is not dynamic, and I have several checkbox fields to populate (all different).

   $('select[multiple="multiple"]').multiselect({
    noneSelectedText: 'Select Town',
    header:  false,
    selectedText: function(numChecked, numTotal, checkedItems){
       return numChecked + ' of ' + numTotal + ' checked';
       }

It's not THAT many fields, though, so I'm willing to hardcode the values if I can get a conditional set up properly, but I think I have my syntax wrong with that, too...

   $('select[multiple="multiple"]').multiselect({
    if ( $(".set_town" ) ) {
       noneSelectedText: 'Select Town',
    }
    header:  false,
    selectedText: function(numChecked, numTotal, checkedItems){
       return numChecked + ' of ' + numTotal + ' checked';
       }