Wordpress & jQuery: "$ is not a function"

If you are trying to add your own jQuery code to WordPress, and have had the error “$ is not a function” show up on Firebug, here is the fix:

Convert all dollar signs ($) to ‘jQuery’

The dollar sign is reserved in WordPress for the Prototype library, which is why it errors out. For example, instead of:

$().ready(function() { $("#select_me").show(); });

Change it to:

jQuery().ready(function() { jQuery("#select_me").show(); });