电机换向器表面氧化膜:asp翻页问题，请指点！

<%

set rs=server.CreateObject("adodb.recordset")
sql="SELECT * FROM pic where pic_id="&request.querystring("pic_id")
on error resume next
rs.Open sql,conn,1,1
set rs1=server.CreateObject("Adodb.recordset")
sql2="select * from Pic where pic_id="&request.querystring("pic_id")+1&"&piccat_id="&request.querystring("piccat_id")&" order by pic_id desc"
on error resume next
rs2.open sql2,conn,1,1
if not rs2.eof then
Response.Write("<a href=showpic.asp?pic_id="&request.querystring("pic_id")+1 &"&piccat_id="&rs("piccat_id")&" >上一张</a>     ")
end if
rs2.close
sql2="select * from Pic where pic_id="&request.querystring("pic_id")-1&"&piccat_id="&request.querystring("piccat_id")&" order by pic_id asc"
on error resume next
rs2.open sql2,conn,1,1

if not rs2.eof then
Response.Write("<a href=showpic.asp?pic_id=" &request.querystring("pic_id")-1 & "&piccat_id="&rs("piccat_id")&" >下一张</a>")
end if
rs2.close
set rs2=nothing
%>
这是一段图片显示翻页代码，但还不完善，到记录的开头还可按上一页，结尾也可按下一页。请高手指点！！！