javascript - Meteor - update var on select change -

i've got dropdown, when user select value, want code executed. question: how can check whether selected value of dropdown has changed?

in 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 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");   } }); 

you can value of select element inside event handler , compare old value had stored:

"change #yearpicker": function(evt) {   var newvalue = $(evt.target).val();   var oldvalue = session.get("year_id");   if (newvalue != oldvalue) {     // value changed, let's   }   session.set("year_id", newvalue); }