This logic is firing when pressing \"Enter\" in the \"Amount\" input, and I don\'t believe it should (it doesn\'t in Chrome). How can I prevent this, and if not prevent it
IE thinks any button element is a submit button (whether you have a form or not). It also handles the press of the Enter key in a form element as an implicit form submission. So, since it thinks you are trying to submit your form, it figures it'll help you out and fire the click event on (what it thinks is) the submit button.
You can attach a keyup event to either the input or the button and check for the Enter key (e.which === 13) and return false;