Problem with Feedback form

Happy day everyone, Recently we just keeping receiving email feedback from [removed]. Under our feedback form we created Php code to fill up the necessary field before they can proceed with submit button. So we find it weird how come we still receiving a blank feedback form everyday. Our website is running for the past 5 years and this the first time we encounter this matter. I call Go Daddy and they said the problem is on the coding of our site. Can somebody help us on this matter? Thanks in advance. gconje