[jQuery] "$ is not defined" error

[Betty]

I get this error in the Firefox error console: "$ is not defined".
it points me to line
$("div#respond>h3").html("Reply to");

I'm sure I've set jQuery properly because it works fine in other
browsers and the other jQuery effects I use can work in Firefox. Only
this part does not work. Actually, it works on my local test computer,
but if I upload the same file to the server, this part gets this
error. I can't understand why.

If you need an example, it's http://myfairland.net/mizong/
#comments">http://myfairland.net/mizong/#comments. The site is in
Chinese. If you put the mouse on the comment part and click the button
that appears, with the Chinese word that means "reply", you can get
the error in Firefox.

This error really frustrates me. If you can help me, I'll appreciate
you very much! Many thanks!

[jQuery] $ is not defined error

[dustinl]

I get this error in the Firefox error console: "$ is not defined" and
it points me to line

$(document).ready( function() {

I have the most up to date jQuery and I am pointing it to the correct
location but I can't figure out why I get this error.  Anybody else
experience this?

[jQuery] $ is not defined error

[Phil Glatz]

I'm modifying the Drupal img_assist module, and trying to add a little
jquery to the popup it creates. When I do, I get this error:

$ is not defined

When I view source, I see the jquery init code at the bottom of the
html for both the page frameset, and for both of the framed pages (the
popup uses frames).