Unclear behavior of the Submit Button causing duplicate submissions

I have had this situation on two different forms in the last two days:

If a person clicks the submit button and there is a delay, then the Submit button has not changed in any way to indicate that it was clicked, causing the user to think that it did not work, and so they click it again, resulting in two submissions (and two payments!).

Because of this, I have a question and a suggestion:

QUESTION:

Can I add something to the submit button that says "Please click only ONCE"?

SUGGESTION:

Can Jotform add in some kind of internal functionality to deal with this automatically? For example, maybe the Submit button changes color immediately upon clicking, so that the user knows that the click was successful?

Thank you for helping me with this issue.

This is the behavior your button has, the message says "Please wait...":

You can change that warning, please check this guide: http://www.jotform.com/help/61-How-to-Change-Form-Warnings

Also, we have a feature to avoid multiple submissions, please check this guide: http://www.jotform.com/help/64-How-to-Set-Unique-Submissions-on-a-Form

Let us know if you need more help, we will be glad to assist you.

Thank you for these options. I will set up the "avoid multiple submissions." By the way, this "please wait" thing is not working--I spoke to one of the users and she said that the button still said "Submit" even after she clicked, and this is why she clicked again. But I'm glad there's another workaround.

Thanks again!

Great to know the workaround provided by our colleague worked.

Now if the form is submitted and your user tries to submit it again, then he/she will receive a message indicating that the form has been already submitted.

Do not hesitate to contact us, we will be glad to assist you.

Do you mean that, now that I've changed the settings, my users will get a warning message when trying to submit a second time? I'm not sure I'm understanding.

Yes, your users will receive a message now when they try to submit your form a second time.