test 3B

by Larry Adams

HTML

<input type='text' id='email'/>
<input type='submit' name='submit' onclick='Javascript:email();'/>

JavaScript

var email = document.getElementById('email');
    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;
 }