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>