Error when trying to add parameters til sql select dataset

I have in my select a parameter in the where clause, and try to add a value to that from a textbox, but keep getting an error. I'm i Newbe to vb.net :-)

This is the code:
Me.Ko_kontaktTableAdapter.Adapter.SelectCommand.Parameters.AddWithValue("@sok", TextBox_sok.Text)

Me.Ko_kontaktTableAdapter.Fill(Me.kalkulasjonDataSet.ko_kontakt)

This is the select:
SELECT     ko_nummer, ko_navn, ko_adresse, ko_postnr, ko_poststed, ko_epost, ko_dato, ko_dato_endret
FROM         ko_kontakt where ko_nummer = @sok

This is the error:
Argument not specified for parameter 'sok' of 'Public Overridable Overloads Function Fill(dataTable As kalkulasjonDataSet.ko_kontaktDataTable, sok As String) As Integer'.