One of the fields in my form is hidden when I post. How do I fix it?

When I edit the form, all fields appear normally, but when I publish, the last field is hidden.

I have checked the active form in your account http://www.jotformz.com/form/70326189527663 and noticed all the fields are appearing when previewing the form. 

May be that the field was set as hidden so it did not show when you previewed it, so I would suggest you to check that the form is not hidden in the field preferences, here's a screen-cast about how to do it: 

Hope this helps.