There are times where you need to validate a form to a data stored in a database without the need to submit the form beforehand. The solution - Ajax (shorthand for asynchronous JavaScript and XML). For example, you are creating a user registration form where obviously, the username to choose from needs to be unique. Instead of validating the username after form submission, wouldn’t it be much friendlier if the form can validate itself  from the server asynchronously in the... Continue Reading