Reverse the words in JavaScript

<SCRIPT>
function revWords(str){
   words = str.split(" ");
   j = words.length - 1;
   backWords = new Array(); 
   for (i=0 ; i < words.length ; i++){
      backWords[j] = words[i];
      j--
   }         
   document.theForm.results.value = backWords.join(" ");
}
</SCRIPT>