How to run JavaScript or jQuery in a Email

Javascript is usually blocked in email clients, simply because of the damage that it can do. Even web-based email services tend to strip out any scripts.

For a very simple example of why, consider this scenario:
You open a spam email, in your open-plan office, while about a dozen of your co-workers go about their daily tasks.
The email uses javascript to take you to an adult video website, and starts playing a random video - after the javascript has cranked your speakers up to the max.
Every time you franticly try to close that website, the javascript opens another one, each one worse than the one before.
Ten minutes later, you're trying to explain to human resources that it wasn't your fault, and you shouldn't be charged with breaching a ton of company rules.
I'm sure you get the picture.

So, unless you're planning to write your own email client, and insist that everyone you want to email uses it, I strongly suspect that you're not going to be able to do what you want.
At least, not directly.

However, you could easily put a hyperlink in your email - you could even apply a graphic of a button to that link if you want it to look like a button - and have the link take you to a web page that runs whatever scripts you want on page load - or put another button on that page.