Enter key down does not open drop down in Mozilla

Question

Enter key does not open drop down in Mozilla. Works fine in Chrome.(Its chrome default behavior)

Trying something like this to achieve it in Mozilla

var self = this;
    $('select').on('keyup', function (e) {
        if (e.keyCode == 13) { $(this).trigger('click'); }
    });

Answer 1

According to this page, the shortcut for Mozilla is Alt+Down Arrow, for select boxes, arrow keys to scroll, Enter to select.