title: Disable backspace and delete key with javascript in IE
body: <p>Anyone know how can I disable backspace and delete key with Javascript in IE? This is my code below, but seems it's not work for IE but fine for Mozilla.</p>
  
  <pre><code>onkeydown="return isNumberKey(event,this)"
  
  function isNumberKey(evt, obj)
  {
  
      var charCode = (evt.which) ? evt.which : evt.keyCode
      if (charCode == 8 || charCode == 46) return false;
  
      return true;
  }
  </code></pre>