asp function to check if an email address is valid

function IsValidEmail(email)
IsValidEmail = true
dim names, name, i, c
names = Split(email, "@")
if UBound(names) <&rt; 1 then
IsValidEmail = false
exit function
end if
for each name in names
if Len(name) <= 0 then
IsValidEmail = false
exit function
end if
for i = 1 to Len(name)
c = Lcase(Mid(name, i, 1))
if InStr("abcdefghijklmnopqrstuvwxyz_-.", c) <= 0 and not IsNumeric(c) then
IsValidEmail = false
exit function
end if
next
if Left(name, 1) = "." or Right(name, 1) = "." then
IsValidEmail = false
exit function
end if
next
if InStr(names(1), ".") <= 0 then
IsValidEmail = false
exit function
end if
i = Len(names(1)) - InStrRev(names(1), ".")
if i <&rt; 2 and i <&rt; 3 then
IsValidEmail = false
exit function
end if
if InStr(email, "..") &rt; 0 then
IsValidEmail = false
end if
end function