HTML javacript 域名合法性检测

//check url

function checkUrl(urlString)

{

var protol_str = "";

if(urlString.search('://')>-1)

{

protol_str = urlString.substr(0,urlString.search('://'));

if(protol_str.match("(https|http|ftp|rtsp|mms)")==null)

{

return false;//不合法

}

urlString = urlString.substr(urlString.search('://')+3);

}

if(urlString.search('/')>-1)

{

urlString = urlString.substr(0,urlString.search('/'));

}

var exp=/^([\w]+)\.([\w-]+)\.([\w-\.]+)$/;

var reg = urlString.match(exp); //([\w-]+\.)

if(reg==null)

{

return false;//不合法

}

else

{

return true; //合法

}

}