Similarly, form data is typically saved in a database on the server.
Because your database contains sensitive information, hackers may attempt to use your form to submit malicious commands to your backend database.
If you haven't already, make sure that you've included the j Query library on your page: Since the name field is required, we simply need to check whether a value for the input exists.
If it exists, we'll apply the valid class and remove any invalid class.
Therefore, we'll create CSS classes to represent these possible outcomes.
Now that we've created a working form, we need to add some j Query and Java Script to validate fields and change the CSS classes that were created earlier.
We apply a little CSS to align the labels and space out the fields: The error messages should only be shown when a field has been entered incorrectly. After the form is submitted, we can reveal the error message by changing the class name with Java Script.To get started, we'll create an HTML page that include a form with the id "contact". It should contain an label, an input (or textarea), and a span that will contain the error message.The form in HTML will look like this: tag improves usability.If you are using a My SQL database, this is called My SQL Injection.To avoid this problem, you must validate form submissions using your server.