jQuery AutoComplete Trigger Change Event

It's better to use the select event instead. The change event is bound to keydown as Wil said. So if you want to listen to change on selection use select like that.

$("#yourcomponent").autocomplete({  
    select: function(event, ui) {
        console.log(ui);
    }
});

this will work,too

$("#CompanyList").autocomplete({
  source : yourSource,
  change : yourChangeHandler
})

// deprecated
//$("#CompanyList").data("autocomplete")._trigger("change")
// use this now
$("#CompanyList").data("ui-autocomplete")._trigger("change")

Here you go. It's a little messy but it works.

$(function () {  
  var companyList = $("#CompanyList").autocomplete({ 
      change: function() {
          alert('changed');
      }
   });
   companyList.autocomplete('option','change').call(companyList);
});

They are binding to keydown in the autocomplete source, so triggering the keydown will case it to update.

$("#CompanyList").trigger('keydown');

They aren't binding to the 'change' event because that only triggers at the DOM level when the form field loses focus. The autocomplete needs to respond faster than 'lost focus' so it has to bind to a key event.

Doing this:

companyList.autocomplete('option','change').call(companyList);

Will cause a bug if the user retypes the exact option that was there before.