ASP判斷E-Mail的合法性，以及過濾郵箱字元

原作者：Loster
'函數名：chk_Email()
'傳回值：布爾值（True為通過，False為未通過）
'參數：email(需要判斷的email，類型：字串) Type_1(是否需要判斷@之後的domain，類型：布爾值)
'Type_2(是否只能是特定域的E-Mail註冊，類型：布爾值) Type_3(一個E-Mail是否只能註冊一次，類型：布爾值)

Const C_maildomain=".com,.com.cn,.net,.net.cn,.org,.org.cn,.gov,.gov.cn,.edu,.edu.cn,.cn,.cc,.biz,.info" '電子郵件可接受的domain
Const C_Lockdomain="bit.edu.cn,loster.org" '特定的域
Function chk_Email(email,Type_1,Type_2,Type_3)
Dim i,k
Dim At
Dim Email_1,Temp
If email="" Then
chk_Email=False
Exit Function
End If
Email_1=Cstr(trim(email))
If Len(Email_1)<5 Then
chk_Email=False
Exit Function
End If
At=False
For i=1 To Len(Email_1)
Temp=Mid(Email_1,i,1)
If Temp="@" Then
at=True
Exit For
End If
Next
If At=False Then
Chk_Email=False
Exit Function
End If

k=0
For i=1 To Len(Email_1)
Temp=Mid(Email_1,i,1)
If Temp="." then
k=k+1
End If
Next
If k=0 Or k>2 Then
Chk_Email=False
Exit Function
End If

If Type_1=True Then
For i=1 To Len(Email_1)
Temp=Mid(Email_1,i,1)
If Temp="@" Then
k=i
Exit For
End If
Next

For i=k To Len(Email_1)
Temp=Mid(Email_1,i,1)
If Temp="." Then
k=i
Exit For
End If
Next
Temp=""
For i=k To Len(Email_1)
Temp=Temp+Mid(Email_1,i,1)
Next
Temp=Cstr(Trim(Temp))
At=False
For i=0 To R_Reader(C_Maildomain,",")
If Temp=Reader(i) Then
At=True
Exit For
End If
Next

Erase Reader
If At=False Then
Chk_Email=False