Server-side validation is more secure but often more tricky to code, whereas client-side (Java Script) validation is easier to do and quicker too (the browser doesn't have to connect to the server to validate the form, so the user finds out instantly if they've missed out that required field! In this tutorial we'll build a simple form with client-side Java Script validation.
You can then adapt this form to your own requirements.
For example, if you are going to send an email confirmation letter, the email address should be included in the form fields, and it should be an email address that works.
Checking for form completion: The first step of form validation is to check, whether the user have entered information in all the fields or not.var attempt = 3; //Variable to count number of attempts ............ Element By Id("username").disabled = true; Element By Id("password").disabled = true; Element By Id("submit").disabled = true; return false; } } }/* Below line is used for online Google font */ @import url(To check, whether the user entered correct form of data, it’s must to apply form validation in any of the form. The expression is: /^[a-z A-Z] $/ The above expression checks whether the input characters in the string is alphabet or not.Executes Java Script whenever a user moves with the mouse the focus away from an element within a form.
In other words, whenever a person first clicks an element, and then clicks anywhere outside of it. Onblur is used when you want to check each element (ie: text, textarea boxes ) individually, and ask the user to correct the input before moving on to the next box.
[A-Z] : It matches characters from uppercase ‘A’ to lowercase ‘Z’. The codes for checking form empty fields are given below: There is an expression that checks whether the string contains only alphabets or not.