I've got a dropdown, but when a user select another value, I want some code to be executed. My question: How can I check whether the selected value of the dropdown has changed?

In my html file:

<template name=jaren>    

    <form id=yearFilter>

        <select class=selectpicker span2 id=yearpicker >

            {{#each jaren}}

                {{#if selectedYear}}

                <option selected value={{_id}}>{{jaar}} {{description}}</option>

                {{else}}

                <option value={{_id}}>{{jaar}} {{description}}</option>

                {{/if}}

            {{/each}}

        </select> 

    </form>

</template>

in my javascript file:

Template.jaren.jaren = function() {

  return Years.find();

}

Template.jaren.selectedYear = function() {

  if (Session.get('year_id') == this._id) {

    return true;

  } else {

    return false;

  }

}

Template.jaren.events({

  'change form#yearFilter #yearpicker': function(event, template) {

    Session.set('year_id', template.find('#yearpicker').value);

    console.log(value changed);

  }

});