How to validate email address in javascript

Recently i have posted how to validate mobile number by javascript, how to validate mobile  number, email address through jquery and now this article will show you how to validate email address using simple javascript or using regular expression in javascript.

here is the code for that just copy and paste the code given below and pass the parameter that is id of email text box this code validate blank field also.

Simple JavaScript Mobile Validation:

function validate_email(tbEMId) {

            var tbEMObj = document.getElementById(tbEMId);

            with (tbEMObj) {

                    apos = value.indexOf("@");

                    dotpos = value.lastIndexOf(".");

                    if (value == '') {

                        alert('field can not be blank');

                    }

                    else if (apos < 1 || dotpos - apos < 2) {

                        alert('please enter correct email');

                        return false;

                    }

             }

        }

 

Regular Expression javascript code:

function IsEmailAddress(txtEmailID) {

    var emlRegex = /^([A-Za-z0-9_\-\.])+\@([A-Za-z0-9_\-\.])+\.([A-Za-z]{2,4})$/;

    var txtemail = document.getElementById(txtEmailID);

    if (mob.test(txtemail.value) == false) {

        alert("please enter correct email.");

        txtemail.focus();

        return false;

    }

    return true;

}