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.

  • Profile Image

    How can I validate a value input in a form against what has been previously submitted?

    Asked by peckhan on May 07, 2015 at 06:21 AM

    Dear Jot Form,


    I would like to validate user input that if the value has already been previously entered, the input is therefore not allowed.

    Can you please also include the javascript code sample if javascript is required?


    Page URL:

  • Profile Image
    JotForm Support

    Answered by Kiran on May 07, 2015 at 10:07 AM

    I understand that you want to have a field on your JotForm to accept unique entries. It is possible to select one of the fields on the form to be as unique question from the form preferences. Please see the screenshot below :

    Hope this information helps. If you are referring to something different, please let us know. We will be happy to help.


  • Profile Image

    Answered by peckhan on May 08, 2015 at 04:06 AM

    Dear Kiran,

    Thanks for your response - the solution helped.

    I have a further question though - the warning message displayed looked like this on my screen - may I know how can I remove the grey/black boxes?



  • Profile Image

    Answered by Boris on May 08, 2015 at 06:08 AM


    Please note that we can only assist with single issue per thread, so kindly open a separate thread in the future for each issue you would like us to help you with. As your second inquiry is related to the initial question, we'll continue here, but please ask other questions in their own threads. Thank you!

    It seems that your image didn't come through, but I suppose you mean the following warning message:

    If so, I'm afraid that we do not currently support customizing the colors / appearance of that error page, because it is the appearance of our internal error messaging page.

    Please let us know if we can help you with anything else, and we will be happy to do so.

    Kind regards,