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

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?

Thanks!

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.

Thanks!

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?

Thanks.

Hello.

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,
Boris