ASP登陆判断

最好能给个例子

<form action="checklogin.asp?send=login" method="post" name="form1"><TR>
<TD><IMG SRC="images/logind_1.gif" WIDTH=768 HEIGHT=74 ></TD>
</TR>
<TR>
<TD><IMG SRC="images/logind_2.gif" WIDTH=768 HEIGHT=1 ></TD>
</TR>
<TR>
<TD height="203" background="images/logind_3.gif"><table width="78%" border="0" align="center" cellpadding="0" cellspacing="0">
<tr>
<td width="32%" height="29">&nbsp;</td>
<td width="30%">用户名：
<input name="userid" type="text" class="inputd" id="userid" maxlength="20"></td>
<td width="38%" rowspan="2"><input type="image" name="imageField" id="imageField" src="images/login_r3.gif" ></td>
</tr>
<tr>
<td height="22">&nbsp;</td>
<td>密&nbsp;&nbsp;码：
<input name="password" type="password" class="inputd" id="password" maxlength="20"></td>
</tr>
<tr>
<td height="30">&nbsp;</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
</tr>
</table></TD>
</TR>
<TR>
<TD><IMG SRC="images/logind_4.gif" WIDTH=768 HEIGHT=1 ></TD>
</TR>
<TR>
<TD><IMG SRC="images/logind_5.gif" WIDTH=768 HEIGHT=105 ></TD>
</TR></form>

checklogin。asp

set rs=server.CreateObject("adodb.recordset")
Sql="Select http,ip,userid,datetime,doomain,daili,id from Camera "
Sql=Sql&" order by datetime desc "
Rs.open Sql,connn,1,1
if not rs.eof then
do while not rs.eof

sql="update Camera set datetime='"&Rs("datetime")&"',ip='"&rs("ip")&"' where domain='"&rs("doomain")&"'"
'conn.execute(sql)
'response.Write(rs("doomain")&"成功<br>")
%>
<%
rs.movenext
loop
else
'response.Write("一条没有")
end if

%>
<%rs.close
set rs=nothing
connn.close
set connn=nothing
%>

<%
Sub SetCookies(root,name,value)
Session(CacheName & name)=value
Response.Cookies(CacheName & root)(name)=value
End Sub
'--------------------------判断是退出还是登陆----调用相应函数
dim str_class
str_class=Request.QueryString("send")
if str_class="login" then
call checklogin
elseif str_class="logout" then
call logout
end if
'-------------------函数调用登陆
function checklogin()
dim userid,password
userid=trim(request.Form("userid"))
password=trim(Request.form("password"))
Strsql="select * from Agents where A_Userid='"& userid &"'"
set rs=server.CreateObject("Adodb.Recordset")
rs.open Strsql,conn,2,2
if rs.eof and rs.bof then
rs.close:set rs=nothing
call FunErr("用户名或密码错误码！|",false)'错误处理
else
if rs("A_Password")<>password then
rs.close:set rs=nothing
call FunErr("密码错误码！|",false)'错误处理
else
response.Cookies("A_Userid")=userid

SetCookies "Admin","AdminName",userid '建立session cookies
SetCookies "Admin","AdminPassword",md5(password,32)
session("yewu")=rs("yewu")
session("username")=rs("company")
session("userid")=rs("id")
rs.close
set rs=nothing
conn.close:set conn=nothing
response.redirect("a_index.asp")
end if
end if
end function

function logout()
response.Cookies("A_Userid")=""
response.Write("<script>parent.window.location='../acts';</script>")
end function

%>