验证域名url地址

function checkUrl(url) {
    var strRegex = '^((https|http|ftp|rtsp|mms)?://)?'
        +'(([0-9a-z_!~*().&=+$%-]+: )?[0-9a-z_!~*().&=+$%-]+@)?' //ftp的user@
        +'(([0-9]{1,3}.){3}[0-9]{1,3}|'// IP形式的URL- 127.0.0.1
        +'([0-9a-z_!~*()-]+.)*'// 域名- www.
        +'[a-z]{2,6})'//域名的扩展名
        +'(:[0-9]{1,4})?'// 端口- :80
        +'((/?)|(/[0-9a-z_!~*().;?:@&=+$,%#-]+)+/?)$';
    return new RegExp(strRegex).test(url);
}