Preventing from re-submitting after submitting his form?

How do I prevent a responder after completing his form not to go back in the browser to re-submit again?

Thanks for your advice. (e c tan)

Hi there - Thanks for reaching out.

You can set a Unique Question on your form to prevent your responder to submit the same information twice. 

Guide: How-to-set-Form-Limits-Based-on-a-Unique-Question 

Alternatively, you can set your form to prevent accepting duplicate submissions from the same location (e.g. IP address)

Guide: How-to-Set-Unique-Submissions-on-a-Form 

Do review and let us know if you need further assistance. We'll be happy to help!