求一段小代码!

<%
    dm="a.www.abc.com"
    dm_a = split（dm, ".")
    up = ubound（dm_a)
    base = ""
    twoji = ""
    sanji = ""
    if up>0 then
        base = dm_a（up-1) & "." & dm_a（up)
    end if 
    if up>1 then
        twoji = dm_a（up-2)
    end if 
    if up>2 then
        sanji = dm_a（up-3)
    end if 

    response.write "base: " & base & "<br>"
    response.write "towji: " & twoji& "<br>"
    response.write "sanji: " & sanji & "<br>"
%>