loop through grid

[EyeTalion]

I'm getting an error msg on this line:

For Each dr In ds.Tables("cards").Rows

I have data in my grid, not sure why I'm getting this msg.

An unhandled exception of type 'System.NullReferenceException' occurred in pcms.exe

Additional information: Object reference not set to an instance of an object.

Dim cmdView As OleDb.OleDbDataAdapter = New OleDb.OleDbDataAdapter("select item_no, activity, account_no from pcms.pcms_item_activity where item_no='" & txtItem.Text & "' and activity='" & txtActivity.Text & "'", objCon)
        ds = New DataSet()
        cmdView.Fill(ds, "cards")
        DataGrid1.DataSource = ds
        DataGrid1.DataMember = "cards"
        objCon.Close()
 
 Dim dr As DataRow
        For Each dr In ds.Tables("cards").Rows
            MsgBox("Whatever")
        Next