Javascript Detect for Safari 3

Today I needed a quick way to detect Safari3 for some specific markup tricks, so I wrote this function.
Thought it might be helpful to someone else.

<script type="text/javascript">
var isSafari3 = (function() {
  var retval = false;
  if (navigator.vendor && navigator.vendor.indexOf('Apple') > -1) {
    var index=navigator.appVersion.indexOf('Version');
    if (index > -1) {
      retval = (parseInt(navigator.appVersion.substring(index+8))==3);
    }
  }
  return retval;
})();
alert(isSafari3);
</script>

Shannon Norrell