Required field function not working and back button on first page is displayed

I have a user that has firefox and they are indicating that the form in question is displaying a button it shouldn't
The front page should not display the back button AND that it is not requiring the name and email or a check in a box that is a required field and that when the next button is selected it doesn't proceed.

Can you tell me what might be causing this and how to best trouble shoot.  I cannot receate the problem myself.  But I have seen it demonstrated on her machine (both a PC and a Mac)

http://form.jotform.us/jsform/50186518325152

Page URL:
http://meridian.systemserenity.com 

As I tried to access your JotForm using direct link, it looks fine and seems to be working fine. However, I see that the issue exists when the form is accessed from the webpage where the form is embedded. It seems that there is a conflict with the other scripts on the webpage. Please try embedding the form using iframe embed method and see if that helps. 

Hope this information helps!