This is a hack, but you can modify the flexselect.js file to raise a custom event when it changes the value of the text field. After any place in the file that calls "this.input.val (" (for example, line 231), insert: trigger ("myCustomEvent"), and then bind to it from your existing code:
$('#selector').bind('myCustomEvent',function(){
alert('myCustomEvent');
});
source
share