What is JotForm?
JotForm is a free online form builder which helps you create online forms without writing a single line of code. No sign-up required.
At JotForm, we want to make sure that you’re getting the online form builder help that you need. Our friendly customer support team is available 24/7.
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 form (http://www.jotform.com/60584050597965) and I wasn't able to replicate your issue. I was able to type in all of the form fields. I was able to enter letters or numbers. I tried this with Google Chrome, Mozilla Firefox, and Internet Explorer 8.
May I know what browser are you using? Can you please try to check if the issue is happening on the another browser. Thank you.