Fire a event onChange every time

Fire a event onChange every time

Hi, I have this piece of code to fire a event when a onChange events occur but I need to change to different option every time:

       $('#search_by').change(function(){
   if($("#search_by option:selected").val() == 4) {
$("#date-selector" ).modal();
   }
        });

But I need to fire the event every time I click the select option with value 4. Any help?