邮件退定功能与邮箱地址验证-PHP源码

<%
dim email
email=request.form("email")
if IsValidEmail(email) then
if request("action")="退订" then
response.redirect "del_email.asp?email="&email
else
response.redirect "add_email.asp?email="&email
end if
else
'response.write "无效的电子邮件格式，请按“后退”按钮，重填一个有效的Email"
response.write"alert('无效的电子邮件格式，请重填一个有效的Email！');"
response.write"Javascript:history.go(-1)《SCRIPT》"
end if

function IsValidEmail(email)
dim names, name, i, c
'Check for valid syntax in an email address.
IsValidEmail = true
names = Split(email, "@")
if UBound(names) <> 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 <> 2 and i <> 3 then
IsValidEmail = false
exit function
end if
if InStr(email, "..") > 0 then
IsValidEmail = false
end if
end function
%>