Email Validation With RegExp In Jquery and Javascript

Email Validation With RegExp In Jquery and Javascript

$(document).ready(function() {

   $('#btnSubmit').click(function() {
 
var sEmail = $('#txtEmail').val();
if ($.trim(sEmail).length == 0) {
alert('Please enter valid email address');
e.preventDefault();
}

// example 1
if (validateEmail(sEmail)) {
alert('Invalid Email Address');
e.preventDefault();

} else {
alert('Email is valid');
}
// example 2
if (validate_email(sEmail)) {
alert('Invalid Email Address');
e.preventDefault();

} else {
alert('Email is valid');
}

// example 3
if (IsEmail(sEmail)) {
alert('Invalid Email Address');
e.preventDefault();

} else {
alert('Email is valid');
}
});
});

function validateEmail(sEmail)
{
var filter = /^([\w-\.]+)@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.)|(([\w-]+\.)+))([a-zA-Z]{2,4}|[0-9]{1,3})(\]?)$/;
if (!filter.test(sEmail)) {
return false;
} else {
return true;
}
}
function validate_email(email)
{
var emailReg = /^([\w-\.]+@([\w-]+\.)+[\w-]{2,4})?$/;
if (!emailReg.test(email)) {
return false;
} else {
return true;
}
}

function IsEmail(email)
{
var regex = /^([a-zA-Z0-9_\.\-\+])+\@(([a-zA-Z0-9\-])+\.)+([a-zA-Z0-9]{2,4})+$/;
if (!regex.test(email)) {
return false;
} else {
return true;
}
}