Validating input in java script
If you validate the form using j Query, you can notice this and alert the user to their mistake instead of submitting the form.
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.
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.
The only difference is that now we want to check whether the email address looks like an email address.
This will buy us free validation from browsers that support HTML5 even if Java Script is turned off.
In client side validation the data is validated in the browser using Java Script before submitting the data to the server.
For example, suppose your user submits the form without entering a mandatory field.
However, if Java Script is turned on, our validation will solve any problems before the browser sees them.
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.Clicking on the label will move the mouse cursor to the input with the id specified in the for attribute.