404 Trick for Directory System

404 Trick for Web Promotion.

search engine's point of view. It is the biggest benefit to have well named pages. Most search engines, like Alta Vista and Yahoo.For example:
Main Category: www.cambodia-tourism.org/index.asp?cat=26 is not memorable as Main
Category: www.cambodia-tourism.org/Hospitality_Catering
Sub Category: wwww.cambodia-tourism.org/Hospitality_Catering/Beverage ...etc

My directory system in table category in MsAccess:

CategoryID   | CategoryTitle      | ParentCategoryID | Description |   Pagename
26             Hospitality & Catering           0                      Hospitality_Catering
34  Berverage      26              Hospitality_Catering/Beverage

As see in index.asp :

<a href="index.asp?cat=<%=CategoryID%>"><%=CategoryTitle%></a>

But now I change it. Instead of passing the Category id with querystring, I need to get the corresponding PageName and redirect to that page. Such as:

<a href="<%=PageName%>"><%=CategoryTitle%></a>

It will now redirect to:
Category: www.cambodia-tourism.org/Hospitality_Catering

Now I need to create the 404.asp page to handle all 404 page not found errors.

404.asp
<%
' Getting page name
dim PageName
PageName = Request.ServerVariables("QUERY_STRING")
%>
<%
' Category id
dim ID
set obj = Server.CreateObject("ADODB.RecordSet")
obj.Open "select CategoryID from TbleCategory where PageName = '"&PageName&"' ", DBCon
if not obj.EOF then
ID = obj.Fields("CategoryID")%>

<%
'Redirect ot Original Page
transferURL = "index.asp?cat=" + CStr(CategoryID)
Server.execute(transferURL)
%>

<%
Else
Error.asp
End if
%>

ADODB.Recordset (0x800A0BB9)
Arguments are of the wrong type, are out of acceptable range, or are in conflict with one another.
/www.cambodia-tourism.ws/404.asp, line 10

Can anyone resolve with this problem?.