title: Javascript alert coming up when not expected
body: <p>I am trying to ensure that all fields of a form are not empty. When there are empty fields this alert comes up as expected, however when all fields are full the alert still comes up. Am I missing something?</p>
  
  <pre><code>var sn = document.myForm.address.length;
  var sna = document.myForm.street.length;
  var su = document.myForm.city.length;
  var st = document.myForm.state.length;
  var usn = document.myForm.username.length;
  
  if (sn || sna || su || st || usn == null) {
      alert("All fields are required. Please ensure you leave no fields blank."); 
      return false;   
  } else {
  
  }
  </code></pre>