Hi,
When you get the
$ is not defined error, it’s almost always because the jquery.js file has not been included or your reference to it is pointing to the wrong location.
So please make sure you have done that, and make sure that it is before all your other jquery code in the HTML.
Moreover, are you using any other javascript library on your page except jQuery? If so, could you please try to modify your custom script and use
noConflict parameter to avoid problems with using jQuery alongside another javascript library.
Best regards,
Michal Legen