Code works in fiddle, but not on webpage

Question

Have tried and tested code in fiddle, the aim is to hide second column when there is a 1 in the dropdown at the top, this works on fiddle, but nothing changes on webpage. An

Answer 1

Enclose your jquery in a document.ready() handler, like so:

$(document).ready(function() {
   $("#selectList").change(function() {
       if ($(this).val() == "1") {
          $(".showMe").hide();
       }
       else {
           $(".showMe").show();
       }
   });
});

Answer 2

Your jQuery code is executing before the elements are in the DOM. Wrap it inside a DOM Ready handler to fix that:

$(function() {
    //your code here
    $("#selectList").change(function() {
        if ($(this).val() == "1") {
           $(".showMe").hide();
        }
        else {
            $(".showMe").show();
        }
    });
});

Your fiddle has an onLoad wrapper (top-left of the page) which automatically wraps your code inside an window.onload function.

window.onload works too but it takes considerably longer than a DOM ready handler to kick in when you have a large page with images and other resources.