submit dataset to database

hi everyone,

i'm a newbee on this forum, and looking for help
This is my problem:
I have tried to fill a dataset from a database
this is done bij a stored procedure
(Getting data from multiple tables!)

Here is the code for that part:
..........

ComCD = New OleDbCommand("cmdTwoInOne", MyConn)

Debug.WriteLine("test select: " & intAr_ID)
ComCD.Parameters.Add("@ArtiestID", OleDbType.Integer)
ComCD.Parameters("@ArtiestID").Value = intAr_ID
ComCD.CommandType = CommandType.StoredProcedure
daCDs.SelectCommand = ComCD
daCDs.FillSchema(dsCD, SchemaType.Source, "tblCD")
daCDs.Fill(dsCD, "tblCD")
.......

When i have the dataset i want to update a row in it
no problem so far.

But when i want to submit the changes of the dataset to the database...it goes wrong
Here is the code how i do that:

Public Sub UpdateCD(ByVal test As DataSet)

If MyConn.State = ConnectionState.Open Then
Else
MyConn.Open()
End If
Dim custCD As OleDbCommandBuilder = New OleDbCommandBuilder(myCommand)
myCommand.Update(test, "tblCD"):confused:

......
in the last rule it goes wrong: mycommand.Update(test,"tblCD")
I'm getting this error:
Value null was found where an instance of an object was required.

I don't no why?
Is it because there are combined tables in the dataset?
If so where can i find information on the net on updating database with combined tables?

Can somebody please help me out!

Thanx guys...

maybe a dumb question, but you are passing the dataset into the Update Sub right? Just trying the easy questions first.

yes i pass it trough the Update....
But i found the problem and i made a work a round
I loaded the dataset with a stored procedure that create combined tables...
i made changes to this dataset and then i wanted to update
de database(DB) table...
But the table in de dataset does not exist in de DB....
I guess this is the problem....

As work around i updated the record directly to the DB and
read back the data into the dataset....

this is not the right way but......:D

I still have a long way to go in .NET!!
If there is a way to update a dataset (to DB) with combined tables,
i would like to hear this....
The resources on www don't tel anything about it!!!!

Thx Cander for your reply