Cookie or IP verification before Survey is completed?

Is there a way to validate/restrict a survey session before the submit button has been clicked?  This way the user does not get all the way to the end of the survey, only to get a message at the end telling them it's not allowed.

Also, is there a way to customize the message that is given to a user that tries to complete a survey for the second time?

Thanks,

David

Unfortunately, there is no way to check the unique submissions (on cookies/IPs) before the submission. The check only comes after the form submission. 

However, you may want to limit the submission based on a unique question. E.g. Unique Email Address or Cell phone number. Here is the help guide that explains this process- How-to-set-Form-Limits-Based-on-a-Unique-Question 

You can even customize the warning message. Here is the article that guides how to do that - How-to-Change-Form-Warnings 

I hope this helps. Let us know if you have further questions.