updating database

[ht]

I have a problem with updateing database.
I fill dataset on form load.
Me.JobDA.Update(KnjiznicaDS, "T_Job")
This line throws error.

if anyone can help I would be grateful
Thanx
The code with witch i fill records:
Private Sub ucitaj()

' definiranje, unos fileova

Dim dir As DirectoryInfo = New DirectoryInfo(Me.Label1.Text)

Dim diar As IO.FileInfo() = dir.GetFiles("*.*")

Dim dra As IO.FileInfo

Dim lokacija As String

lokacija = Label1.Text

'Definiranje Datatable

Dim Topis As DataTable = KnjiznicaDS.T_opis

Dim NewRowO As DataRow

'Punjenje dataseta sa fileovima

For Each dra In diar

NewRowO = KnjiznicaDS.Tables("T_opis").NewRow()

NewRowO("ID_Job") = Me.Label2.Text

NewRowO("Lokacija_dat") = lokacija

NewRowO("Naziv_dat") = dra

Topis.Rows.Add(NewRowO)

Me.BindingContext(KnjiznicaDS, "T_job").Position =
Me.BindingContext(KnjiznicaDS, "T_job").Count - 1

Next