Getting this error:Microsoft VBScript runtime error '800a01a8'

My lookup function that creates a.txt lookuptable is giving thi error. The function looks like this:
Function loadLookupList(ByVal luList, ByVal keyType, ByVal tblName, ByVal sortField)
'
' load table into application dictionary
'
Dim oDB, oConn, oRs, sqlStmt
Dim oFSO, oText, fn

fn = Server.MapPath("/virtual") & "\lookups\lookup" & tblName & ".txt"
sqlStmt = "SELECT * FROM " & tblName
If sortField <> "" THen sqlStmt = sqlStmt & " ORDER BY " & sortField

Set oFSO = Server.CreateObject("Scripting.FileSystemObject")
Set oText = oFSO.CreateTextFile(fn,True)

Set oDB = New clsDB
result = oDB.Open
If Not result Then Exit Function
Set oConn = oDB.Connection

Set oRs = oConn.Execute(sqlStmt)
While Not oRs.Eof
key = oRs(0)
buffer = ""
For i = 1 to oRs.Fields.Count - 1
buffer = buffer & "#" & oRs.Fields(i)
Next
value = Mid(buffer, 2) ' strip leading #
oText.WriteLine(key & "," & value)
oRs.MoveNext
Wend
oText.Close

result = luList.LoadValues(fn, keyType)

loadLookupList = (result = 0)

Set oFSO = Nothing
Set oText = Nothing
Set oRs = Nothing
Set oConn = Nothing


End Function

The result = luList.LoadValues(fn, keyType), is giving this error :

Microsoft VBScript runtime error '800a01a8'

Object required: 'luList'

//includes/DBLookup.asp, line 519

Does anyone has any idea why ??? Your is very much needed.

Thanks.
Suran

The function looks okay. Can you post the code that is calling the function? Apparently the first parameter being passed isn't a valid object... that's what it seems to me. However, I am not an expert at ASP, so I may be wrong.

This is the calling function:

Function initLookup()
initLookup = loadLookupList(luProdClass, 12, "ProdClass", "Name")
End Function

Thanks for helping
Suran

Have you identified line 519?
My initial thoughts are that the object luList has not been initialised before calling the function, or that the luList you are passing is not set up correctly.