Also, the ‘@’ must not be the first character of the email address, and the last dot must at least be one character after the ‘@’ sign.
The following example shows how to validate an entered email address.
An email address must contain at least a ‘@’ sign and a dot (.).
If they click the input, it will activate the input. It's basically the secret selector for testing if an input currently has a value or not.
There is no IE or Firefox support though, which is particularly difficult to navigate around.
All credit cards are 16 digits and the 16th digit can be calculated based on the first 15 numbers.
This means you can use Java Script to check for, and alert the user to, credit card typos.There are two types of validation: client side validation and server side validation.In client side validation the data is validated in the browser using Java Script before submitting the data to the server.Java Script form validation is a great way to help your users avoid mistakes when filling out a form Alternatively, if you want to protect your server from malicious users, then you should use server side validation because Java Script can be easily bypassed.For example, suppose you wanted to validate a credit card.I'd say if the form is short and an obvious pattern (like sign up or log in), you could use the placeholder visual pattern, but use real labels instead. You don't need to do any tricky cursor stuff, because it's all semantically wired up already. In order to do that, we'll need to know if the input is empty or not.