js比較字符數組元素是否重複

<SCRIPT LANGUAGE="JavaScript">
<!--
function mm(a)
{
   return /(\x0f[^\x0f]+)\x0f[\s\S]*\1/.test("\x0f"+ a.join("\x0f\x0f") +"\x0f");
}

var ary = new Array("111","22","33","112");
alert(mm(ary))
//-->
</SCRIPT>