javascript form validation code code example
Example 1: how to set validation for email in javascript
<script language="javascript">
function checkEmail() {
var email = document.getElementById('txtEmail');
var filter = /^([a-zA-Z0-9_\.\-])+\@(([a-zA-Z0-9\-])+\.)+([a-zA-Z0-9]{2,4})+$/;
if (!filter.test(email.value)) {
alert('Please provide a valid email address');
email.focus;
return false;
}
}</script>
Example 2: html form validation
<form action="">
<label for="name">Username</label>
<input id="name" type="text" required />
<label for="Email">Email</label>
<input id="Email" type="text" required />
</form>
Example 3: javascript login validation
<script language = "JavaScript">
function validate() {
var username = document.getElementById("username").value;
var password = document.getElementById("password").value;
if (username == null || username == "") {
alert("Please enter the username.");
return false;
}
if (password == null || password == "") {
alert("Please enter the password.");
return false;
}
alert('Login successful');
}
</script>
Example 4: javascript form validation
<form name="myForm" action="/action_page.php" onsubmit="return validateForm()"
method="post">
Name: <input type="text" name="fname">
<input type="submit" value="Submit">
</form>