关于投票的问题

我想做到一个ip投票一次后，在tpip表中存储其ip和时间,2分钟只能不能再进行投票.现在遇到一个问题就是.如果他是第一次投票，该如何判断.我用total=rs1.recordcount无法得到记录数目

<!--#include   file= "conn1.asp "-->

<%      

id=trim(request.querystring( "userid "))
username=trim(request.querystring( "username "))
Caption=trim(request.querystring( "caption "))


come_ip   =   Request.ServerVariables( "HTTP_X_FORWARDED_FOR ")
if   come_ip   =   " "     then
                come_ip=Request.ServerVariables( "remote_addr ")
end   if
if   instr(come_ip, " ' ")> 0   then
                come_ip= "0.0.0.0 "
end   if


    '+==========================================================+
    '+==========================================================+
   
set   rs1=server.createobject( "adodb.recordset ")
sql   =   "select   *   from   tpip   where   ip= ' "   &   come_ip   &   " ' "
rs1.open   sql,conn,1,1
if   not   rs1.eof   then
total=rs1.recordcount
response.write(total)

  if     abs(DateDiff( "n ",   Now,   rs1( "dtime ")))= <2     then
response.write( "错误信息 ")
else   if     abs(DateDiff( "n ",   Now,   rs1( "dtime ")))=> 2   or   total   <=0   then

set   rs2=server.createobject( "ADODB.recordset ")
sql= "select   *   from   Dv_bbs1   where   postuserid= "   &id&   "and   dateandtime=# "   &   caption   &   "#   "
rs2.open   sql,conn,1,2
rs2( "isvote ")=rs2( "isvote ")+1
response.write   "您已经为 "   &   username   &   "投票成功 "  
rs2.update
rs2.close
end   if
end   if




rs1.update
rs1.close
end   if
set   rs=server.createobject( "ADODB.recordset ")
rs.Open   "select   *   from   tpip ",conn,1,3

if   not   rs.eof   and   not   rs.bof   then
    rs.addnew
    rs( "ip ")=come_ip
    rs( "dtime ")=now()
    rs.update
    rs.close
end   if


------解决方案--------------------
如果用total=rs1.recordcount无法取出正确值的话，可以考虑使用sql = "select count(id) as expr1 from tpip where ip= ' " & come_ip & " ' "来实现。取值的时候取total=rs1( "expr1 ")即可。
------解决方案--------------------
给个session 如果投了票就给它个值， 这样就好恶劣
------解决方案--------------------
select count(ip) from tpip where ip= 'IP地址 ' and datediff(minute,时间,now())> 2
------解决方案--------------------
可考慮用COOKIE
------解决方案--------------------
俺以前也这么限制过，可有人更狠 用ADSL拨号+按键精灵