问如何使用ASP而不是ASP.net获取根url

EN

function getSiteRootUrl()
    dim siteRootUrl, protocol, hostname, port

    if Request.ServerVariables("HTTPS") = "off" then
        protocol = "http"
    else
        protocol = "https"
    end if
    siteRootUrl = protocol & "://"

    hostname = Request.ServerVariables("HTTP_HOST")
    siteRootUrl = siteRootUrl & hostname        

    port = Request.ServerVariables("SERVER_PORT")
    if port <> 80 and port <> 443 then
        siteRootUrl = siteRootUrl & ":" & port
    end if

    getSiteRootUrl = siteRootUrl
end function

getSiteURL()

Function getSiteURL()

    dim port
    dim https 
    dim domainname
    dim filename
    dim querystring
    dim fullpath
    dim url

    port = "http" 
    https = lcase(request.ServerVariables("HTTPS")) 
    if https <> "off" then port = "https" 
    domainname = Request.ServerVariables("SERVER_NAME") 
    filename = Request.ServerVariables("SCRIPT_NAME") 
    querystring = Request.ServerVariables("QUERY_STRING") 
    fullpath = port & "://" & domainname & Request.ServerVariables("SCRIPT_NAME")
    filename = right(fullpath, InStr(StrReverse(fullpath), StrReverse("/")))

    url = Replace(fullpath, filename, "/")

    response.write url & "<br>" 
end Function 

Function GetSitePath()
    Dim address, port, url
    address = "http://"
    If LCase(Request.ServerVariables("HTTPS")) = "off" Then address = "https://"
    address = address & Request.ServerVariables("SERVER_NAME")
    port = Request.ServerVariables("SERVER_PORT")
    If port <> 80 And port <> 443 Then address = address & ":" & port
    url = Request.ServerVariables("URL")
    address = address & Left(url, InstrRev(url, "/"))
    GetSitePath = address
End Function