JotForm is a free online form builder which helps you create online forms without writing a single line of code. No sign-up required.
We believe that if one user has a question, there could be more users who may have the same question. This is why many of our support forum threads are public and available to be searched and viewed. If you’d like help immediately, feel free to search for a similar question, or submit your question or concern.
I checked your website link: http://www.custommadeflags.com/newsletter.html, and I see that the form is loaded properly without error.
I made a test submission to see if everything works, it directed me to the thank you page as expected.
I've also checked your account limits and I see that you are far from reaching your quota.
Everything seems to be okay, do let us know if you are still experiencing problems on this.