login page with email validation example

Example 1: code for email verification in front end using javascript

function validateEmail(email) {
    const re = /^(([^<>()\[\]\\.,;:\s@"]+(\.[^<>()\[\]\\.,;:\s@"]+)*)|(".+"))@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\])|(([a-zA-Z\-0-9]+\.)+[a-zA-Z]{2,}))$/;
    return re.test(String(email).toLowerCase());
}

Example 2: email validation in javascript

<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
<title>JavaScript form validation - checking email</title>
<link rel='stylesheet' href='form-style.css' type='text/css' />      
</head>
<body onload='document.form1.text1.focus()'>
<div class="mail">
<h2>Input an email and Submit</h2>
<form name="form1" action="#"> 
<ul>
<li><input type='text' name='text1'/></li>
<li> </li>
<li class="submit"><input type="submit" name="submit" value="Submit" onclick="ValidateEmail(document.form1.text1)"/></li>
<li> </li>
</ul>
</form>
</div>
<script src="email-validation.js"></script>
</body>
</html>