TypeError: 'undefined' is not a function (evaluating '$(document)')

Use jQuery's noConflict. It did wonders for me

var example=jQuery.noConflict();
    example('span#resultado').text("Hello, dude!");

That is, assuming you included jQuery on your HTML

<script language="javascript" type="text/javascript" src="https://ajax.googleapis.com/ajax/libs/jquery/1.7.2/jquery.min.js"></script>

Wordpress uses jQuery in noConflict mode by default. You need to reference it using jQuery as the variable name, not $, e.g. use


instead of


You can easily wrap this up in a self executing function so that $ refers to jQuery again (and avoids polluting the global namespace as well), e.g.

(function ($) {