[Q] Login và Log-Out

Bạn tham khảo cái code này của mình nhé, nếu không hiểu thì cứ hỏi. Mình viết tất cả theo code của ASP, có lẽ hơi khó hiểu một chút.
Cơ sở dữ liệu gòm có các trường sau: ID, Ten, MatKhau và CapBac
<%
dologin = request.form("DangNhap")
usn = request.form("username")
psw = request.form("password")
if request.cookies("logoncookie")("cookname") <> "" then
usn = request.cookies("logoncookie")("cookname")
psw = request.cookies("logoncookie")("cookpass")
dologin = "yes"
end if
if request.form("Thoat")="thoat" then
dologin = "no"
session("DangNhap")="no"
session("username") = ""
session("admin") = "no"
session("member") = "no"
response.cookies("logoncookie").expires = date -1
end if

if dologin ="yes" then
set rs1 = server.createobject ("ADODB.recordset")
MYSQL = "SELECT * FROM ThanhVien WHERE Ten = '" & usn & "'"

rs1.open MYSQL, Conn, 1, 3
if not rs1.EOF or not rs1.BOF then if psw = (rs1("MatKhau")) then session("DangNhap") = "yes"
session("username") = usn
if rs1("CapBac") = "member" then session("member") = "yes"
if rs1("CapBac") = "admin" then
Session("username") = rs1("Ten")
session("member") = "yes"
session("admin") = "yes"
end if
if request.form("rem") = "yes" then
response.cookies("logoncookie").Expires = date + 365
response.cookies("logoncookie")("cookname")= usn
response.cookies("logoncookie")("cookpass")= psw
end if
else
session("DangNhap") = "no"
errmess="M***7853;t kh***7849;u b***7841;n nh***7853;p không ***273;úng"
end if
else
errmess="<p align=center>B***7841;n nh***7853;p không ***273;úng tên truy nh***7853;p"
end if
rs1.close()

end if

if session("DangNhap") = "yes" then
call logonyes
else

call logonno
response.write errmess
end if

function logonno()
Response.Write "<form method=""post"" action=""" & Request.ServerVariables("SCRIPT_NAME") & "?" & Request.ServerVariables("QUERY_STRING") & """ name=""form1"" onSubmit=""return ktForm();"">" & vbNewLine & _
" <table border=""0"" cellpadding=""0"" cellspacing=""0"" style=""border-collapse: collapse"" bordercolor=""#111111"" width=""100%"" id=""AutoNumber36"">" & vbNewLine & _
" <tr>" & vbNewLine & _
" <td width=""50%""><p align=""right"">Tên truy nh***7853;p&nbsp;</td>" & vbNewLine & _
" <td width=""50%"">" & vbNewLine & _
" <input type=""text"" class=""inputtext"" name=""username"" size=""9""></td>" & vbNewLine & _
" </tr>" & vbNewLine & _
" <tr>" & vbNewLine & _
" <td width=""100%"" colspan=""2"">" & vbNewLine & _
" <img border=""0"" src=""images/spacer.gif"" width=""1"" height=""5""></td>" & vbNewLine & _
" </tr>" & vbNewLine & _
" <tr>" & vbNewLine & _
" <td width=""50%""><p align=""right"">M***7853;t kh***7849;u&nbsp;</td>" & vbNewLine & _
" <td width=""50%""><input type=""password"" class=""inputtext"" name=""password"" size=""9""></td>" & vbNewLine & _
" </tr>" & vbNewLine & _
" <tr>" & vbNewLine & _
" <td width=""100%"" colspan=""2"">" & vbNewLine & _
" <img border=""0"" src=""images/spacer.gif"" width=""1"" height=""5""></td>" & vbNewLine & _
" </tr>" & vbNewLine & _
" <tr>" & vbNewLine & _
" <td width=""50%"" colspan=""2"" align=""center"">" & vbNewLine & _
" <p>Nh***7899; m***7853;t kh***7849;u <input type=""checkbox"" name=""rem"" Value=""yes""></td>" & vbNewLine & _
" </tr>" & vbNewLine & _
" <tr>" & vbNewLine & _
" <td width=""100%"" colspan=""2"">" & vbNewLine & _
" <img border=""0"" src=""images/spacer.gif"" width=""1"" height=""5""></td>" & vbNewLine & _
" </tr>" & vbNewLine & _
" <tr>" & vbNewLine & _
" <td width=""100%"" colspan=""2""><p align=""center""><a href=""?HomePage=WWW.TREVIETNAM.COM&Menu=DangKy""> ***272;***259;ng kư</a>" & vbNewLine & _
" <input type=""hidden"" name=""DangNhap"" Value=""yes"">" & vbNewLine & _
" <input type=""submit"" name=""login"" class=""inputbutton"" Value=""***272;***259;ng nh***7853;p"">" & vbNewLine & _
" </td>" & vbNewLine & _
" </tr>" & vbNewLine & _
" <tr>" & vbNewLine & _
" <td width=""100%"" colspan=""2"">" & vbNewLine & _
" <img border=""0"" src=""images/spacer.gif"" width=""1"" height=""5""></td>" & vbNewLine & _
" </tr>" & vbNewLine & _
" <tr>" & vbNewLine & _
" <td width=""100%"" colspan=""2""><p align=""center""><a href=""?HomePage=WWW.TREVIETNAM.COM&Menu=XinLaiMat Khau"">Quên m***7853;t kh***7849;u?</a></td>" & vbNewLine & _
" </tr>" & vbNewLine & _
" </table></form>" & vbNewLine
end function

function logonyes()
Response.Write "<center><p>Chào b***7841;n <a href=""user/profile.asp"" target=""_bank""><font color=""#ff0000""><b>" & session("username") & "</b></font></a><br>Xin chúc b***7841;n m***7897;t ngày<br> th***7853;t vui v***7867; và t***7889;t lành<br><br></center>"

If session("admin") = "yes" then
response.write "<center>B***7841;n hăy nh***7845;n vào liên k***7871;t<br>d***432;***7899;i ***273;ây ***273;***7875; th***7921;c hi***7879;n các<br>ch***7913;c n***259;ng ***273;i***7873;u khi***7875;n<br>c***7911;a ng***432;***7901;i ***273;i***7873;u hành<br><br><a href=""Admin/control_panel.asp"">Ch***7913;c n***259;ng c***7911;a Admin</a>"
End If
Response.Write "<center>" & vbNewLine & _
" <form name = ""form1"" method=""post"" action=""" & Request.ServerVariables("SCRIPT_NAME") & "?" & Request.ServerVariables("QUERY_STRING") & """>" & vbNewLine & _
" <input type=""hidden"" name=""Thoat"" Value=""thoat"">" & vbNewLine & _
" <input type=""submit"" name=""logoff"" value=""" & Session("username") & " thoát?"" class=""inputButton"">" & vbNewLine & _
" </form>" & vbNewLine & _
"</center>" & vbNewLine
end function
%>

Cám ơn rất nhiều.

Nhưng mình phải từ từ coi lại. Có gì mình sẽ hỏi liền.