JavaScript Tutorial 2: HTML Form - email validation

How to email validation in javascript here are the steps  its easy to do email validation in javascript

Example of valid email id


    yourweb@example.me.net
    yoursite@example.com
   you.example@example.org

Example of invalid email id

   .example@mysite.org [ an email should not be start with "." ]
    example()*@gmail.com [ here the regular expression only allows character, digit, underscore, and dash ]
    example..1234@Gmail.com [double dots are not allowed]
    mysite.example.com [@ is not present]
    mysite@.com.my [ tld (Top Level domain) can not start with dot "." ]
    @you.example.net [ No character before @ ]
    example123@gmail.b [ ".b" is not a valid tld ]
    example@.org.org [ tld can not start with dot "." ]


JavaScript code to validate an email id

var filter = /^([a-zA-Z0-9_\.\-])+\@(([a-zA-Z0-9\-])+\.)+([a-zA-Z0-9]{2,4})+$/;

if (!filter.test(mail)) {
    alert('Please provide a valid email address');
    email.focus;
    return false;
  }