TypeError：$（selector）为null

Question

I have a web page that redirects to another page on click. On the second page I have this:

<?php if(isset($_POST['tab1'])) { ?>
  <script>$('#home').trigger('click'); </script> 
<?php }?>    

The $_POST comes back ok, only I get this error in the console for the jquery:

In firebug:

TypeError: $("#home") is null

Or in Chrome:

$('#home').trigger('click');

If I run this: alert(document.getElementsByTagName('#home'));

I get a alert with: [object HTMLCollection] as undefined

If I view the source I can see my jquery there:

<script type="text/javascript" src="https://ajax.googleapis.com/ajax/libs/jquery/1.6.2/jquery.js"></script>
<script type="text/javascript" src="https://ajax.googleapis.com/ajax/libs/jqueryui/1.8.16/jquery-ui.js"></script>
<script>
!window.jQuery && document.write('<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.6.2/jquery.js"><\/script>');
</script>

Any ideas on why the jquery fails?

Answer 1

Try putting it in a document ready to ensure that the DOM is loaded before manipulating it:

<?php if(isset($_POST['tab1'])) { ?>
    <script>$(function() { $('#home').trigger('click'); } );</script>
<?php }?>