i have javascript code posted it in this forum before but I get a help with out full understanding...

<script type="text/javascript">
function CK() {
var str = new String();
str = "man mr how me";
var arrResult = new Array();
var op = new Array('man','HOW','ME');
  for(var i=0; i< op.length; i++) {
  var pattern = ""+op[i]+"";
  arrResult = str.match( pattern );
 alert( "Found: " + arrResult.length + ' And Patter: ' + pattern );

<body onload="CK()">

i want to use:
var pattern = /+op[i]/gi;
or something like that... i means i want show to me how=How, man=man, Me=me

how i can get it