Unfortunately, memberships are not accessible on iPads at this time.
Please instead use a non-tablet computer. Make sure you are working in an up-to-date browser to reduce log-in issues. We recommend you use Firefox, Chrome or Safari I've provided links to the download pages for each of them below.
Firefox - http://www.getfirefox.com/
Chrome - http://www.google.com/chrome
Safari - http://www.apple.com/safari/