[jQuery] Check function ... Not working in JQuery. Please, is urgent. Thank You.

Hello,

I am applying a function (tinymce) to some text areas.
However I need to check before if this function exists (if its js file
was loaded).

If I would use JS I would do this:

$(document).ready(function() {

if (typeof (tinymce) !== "undefined") {

$('textarea.Editor-Base').tinymce({
// ...

This is not working. Even if the function tinymce is present it is not
applied.
I removed the code line (if (typeof (tinymce) !== "undefined") {) and
not tinymce runs.

But I really need to test it.

This was working when I was not using JQuery ...

Any idea how to do this?

Thanks,
Miguel