simple JavaScript in rails -

i wanted trigger alert function when click html tags.

# app/assets/javascripts/home.js  function alertbox() {   window.alert("gogo"); } document.getelementbyid("java-test").onclick = function() { alertbox() };   # app/views/home/index.html.erb  <h1>please <span id="java-test">pop</span> up~</h1> 

it's working when use <span onclick="alertbox()"> wanted make html files little bit clearer. missing?

i think i'm totally wrong on understanding how works on ruby on rails. of comments huge me. thanks!

it's because dom isn't ready, span isn't there script find when getelementbyid. try this, instead:

# app/assets/javascripts/home.js  function alertbox() {   window.alert("gogo"); } window.onload = function () {     document.getelementbyid("java-test").onclick = function() {         alertbox();     }; };   # app/views/home/index.html.erb  <h1>please <span id="java-test">pop</span> up~</h1>