Implementing input validation is the best way to locate and prevent the issue of manipulation of the public-facing web form used by customers to order products. Input validation is a technique that checks and filters any user input that is sent to an application before processing it. Input validation can help to ensure that the user input conforms to the expected format, length and type, and does not contain any malicious characters or syntax that may alter the logic or behavior of the application. Input validation can also reject or sanitize any input that does not meet the validation criteria .