关于跳转页面的问题? 谢谢!

dim fln
fln=Request.Form("fn")
if fln="sub" then
set conn=Server.CreateObject("ADODB.Connection")
conn.Provider="Microsoft.Jet.OLEDB.4.0"
conn.Open Server.MapPath("db/YH.mdb")

set rs=Server.CreateObject("ADODB.Recordset")
sql="SELECT * FROM YH WHERE username='" & Request.Form("yonghu") & "' AND password='" & Request.Form("mima") & "'"
rs.open sql,conn
if not rs.EOF then
 rs.Close
 conn.Close
 Response.Redirect("serach.asp")
end if
end if


请问代码有什么问题?为什么总是跳不过去? 谢谢!