代码片段三：
<%
dim ComeUrl,cUrl,AdminName
ComeUrl=lcase(trim(request.ServerVariables("HTTP_REFERER")))
if ComeUrl="" then
response.write "<br><p align=center><font color='red'>对不起，为了系统安全，不允许直接输入地址访问本系统的后台管理页面。</font></p>"
response.end
else
cUrl=trim("http://" & Request.ServerVariables("SERVER_NAME"))
if mid(ComeUrl,len(cUrl)+1,1)=":" then
cUrl=cUrl & ":" & Request.ServerVariables("SERVER_PORT")
end if
cUrl=lcase(cUrl & request.ServerVariables("SCRIPT_NAME"))
if lcase(left(ComeUrl,instrrev(ComeUrl,"/")))<>lcase(left(cUrl,instrrev(cUrl,"/"))) then
response.write "<br><p align=center><font color='red'>对不起，为了系统安全，不允许从外部链接地址访问本系统的后台管理页面。</font></p>"
response.end
end if
end if
AdminName=replace(session("AdminName"),"'","")
if AdminName="" then
call CloseConn()
response.redirect "login.asp"
response.End()
end if
sql="select UserName from Admin where UserName='" & session("AdminName") & "' and Password='" & session("AdminPassword") & "'"
set rs=conn.execute(sql)
if rs.eof and rs.bof then
rs.close
response.Redirect("login.asp")
response.End()
end if
%> | 
