Facts for developer

When allowing users to enter data into our website, we need to check whether the data is entered by the human. Otherwise, people will use robots to push the bulk of unwanted data into the website. It will cause a lot of problems like XSS attack or increase server load to down the website. CAPTCHA is one of the methods to prevent robots from entering data. CAPTCHA can be text-based, audio-based or graphics-based random code generated dynamically. On submitting user input, this code will be mandatory which will help to capture robot not entering captcha code. In this tutorial, I have a contact form to get the user input. This form includes name, email, message subject and message body fields to get messages from the user. I have created a random captcha code and stored it in a session. This captcha code will be displayed in the contact form which should be entered by the user to submit their messages. I have the server side validation to check whether the code is no...