document.getElementById('your-form-id').addEventListener('submit', function(event) {
var emailField = document.getElementById('email-field-id');
var regex = /^[\w-\.]+@([\w-]+\.)+[\w-]{2,4}$/; // Regex for validating email
if (!regex.test(emailField.value)) {
alert('Please enter a valid email address.');
event.preventDefault(); // Prevent form submission
}
});
