JavaScript 正则表达式 验证网址

<script language="JavaScript">
2<!--
3 function IsURL(str_url){
4        var strRegex = "^((https|http|ftp|rtsp|mms)?://)" 
5        + "?(([0-9a-z_!~*'().&=+$%-]+: )?[0-9a-z_!~*'().&=+$%-]+@)?" //ftp的user@ 
6        + "(([0-9]{1,3}\.){3}[0-9]{1,3}" // IP形式的URL- 199.194.52.184 
7        + "|" // 允许IP和DOMAIN（域名）
8        + "([0-9a-z_!~*'()-]+\.)*" // 域名- www. 
9        + "([0-9a-z][0-9a-z-]{0,61})?[0-9a-z]\." // 二级域名 
10        + "[a-z]{2,6})" // first level domain- .com or .museum 
11        + "(:[0-9]{1,4})?" // 端口- :80 
12        + "((/?)|" // a slash isn't required if there is no file name 
13        + "(/[0-9a-z_!~*'().;?:@&=+$,%#-]+)+/?)$"; 
14        var re=new RegExp(strRegex); 
15  //re.test()
16        if (re.test(str_url)){
17            return (true); 
18        }else{ 
19            return (false); 
20        }
21    }
22-->
23</script>