Do something when a date is selected, preserving BookThatApp's handling for availability purposes

bta-onselect.js

<script type="text/javascript">
bta_callbacks = {};

// invoked after availability data from BookThatApp is loaded via Ajax.
bta_callbacks["loaded"] = function(data) {
    var onStartSelect = $('#booking-start').datepicker('option', 'onSelect'),
        onFinishSelect = $('#booking-finish').datepicker('option', 'onSelect');
    
    $('#booking-start').datepicker('option', 'onSelect', function(date) {
        onStartSelect.call(this, date);
    });
    
    $('#booking-finish').datepicker('option', 'onSelect', function(date) {
        onFinishSelect.call(this, date);
    });
};
</script>