title: document.getElementById('btnid').disabled is not working in firefox and chrome
body: <p>I'm using JavaScript for disabling a button. Works fine in IE but not in FireFox and chrome, here is the script what I'm working on:</p>
  
  <pre><code>function disbtn(e) { 
      if ( someCondition == true ) {
         document.getElementById('btn1').disabled = true;
      } else {
         document.getElementById('btn1').disabled = false;
      }
  </code></pre>
  
  <p>And in my html I have: </p>
  
  <pre><code>&lt;input type="button" id="btn1" value="submit" /&gt;
  </code></pre>