1/*html*/
2<select id="sel" onchange='alert("changed")'>
3 <option value='1'>One</option>
4 <option value='2'>Two</option>
5 <option value='3' selected>Three</option>
6</select>
7
8/*Function js*/
9var select = document.querySelector('#sel'),
10 input = document.querySelector('input[type="button"]');
11select.addEventListener('change',function(){
12 alert('Yare yare daze');
13});
14
15/*RESULT*/
16/*When change value trigger alert('Yare yare daze') */
17
18
19
20