IdfDocumentum in Vb.Net .dll? And How do I IdfDocumentum convert to 'object'

[demetkbkc]

Hi,
I use dll is DFCLib but is it true?

I try;

Dim sysObj As IDfSysObject
Dim perObj As IDfPersistentObject
Dim session As IDfSession
Dim document As IDfDocument
Dim Id As IDfId
Dim nesne As Object = Nothing

Dim strSQL As String = " dm_document where r_object_id='" & itemID.ToString() & "'"
sysObj = Nothing
Id = m_DfClientX.getId(itemID)
perObj = session.getObjectByQualification(strSQL)
sysObj = CType(perObj, IDfSysObject)
nesne = sysObj.getContent()
document = CType(sysObj.getContent(), IDfDocument)

***exception line

I dont convert object to IdfDocument in VB.NET..
Java is convert >>doc = (IDfDocument) session.getCont ent()

How do I Vb.Net???

Help me please.
Thanks