请高手把此段php代码转换为js,谢谢

PHP code

$str="http://www.baidu.com/s?wd=js%E8%8E%B7%E5%8F%96php%E5%8F%98%E9%87%8F&tn=ichuner_1_dg&ie=utf-8";preg_match("/(?:baidu.+?wd=|baidu.+?kw=|baidu.+?word=|soso.+?w=|sogou.+?query=|bing.+?q=|114.+?kw=)([^&]*)/i",$str,$matches);$keystr=urldecode($matches[1]);

JScript code

            $str="http://www.baidu.com/s?wd=js%E8%8E%B7%E5%8F%96php%E5%8F%98%E9%87%8F&tn=ichuner_1_dg&ie=utf-8";            var re = /(?:baidu.+?wd=|baidu.+?kw=|baidu.+?word=|soso.+?w=|sogou.+?query=|bing.+?q=|114.+?kw=)([^&]*)/i            alert($str.match(re)[1])
[解决办法]
JScript code
<script>var str = "http://www.baidu.com/s?wd=js%E8%8E%B7%E5%8F%96php%E5%8F%98%E9%87%8F&tn=ichuner_1_dg&ie=utf-8";var matches = str.match(/(?:baidu.+?wd=|baidu.+?kw=|baidu.+?word=|soso.+?w=|sogou.+?query=|bing.+?q=|114.+?kw=)([^&]*)/i);var keystr = decodeURI(matches[1]);alert(keystr)</script>