function isvalidemail(email)
dim names, name, i, c
isvalidemail = true
names = split(email, @)
if ubound(names) 1 then
isvalidemail = false
exit function
end if
for each name in names
if len(name) isvalidemail = false
exit function
end if
for i = 1 to len(name)
c = lcase(mid(name, i, 1))
if instr(abcdefghijklmnopqrstuvwxyz_-., c) 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), .) isvalidemail = false
exit function
end if
i = len(names(1)) - instrrev(names(1), .)
if i 2 and i 3 then
isvalidemail = false
exit function
end if
if instr(email, ..) > 0 then
isvalidemail = false
end if
end function
%>