Update table in PostGreSQL using Visual Basic 2008

[paulache]

Hi guys!

I need some help. I`ve created a database in postgre and linked it to vb. All good till now.
The problem: I want that when i press the "rezerva" button the field "disponibilitat e" to update to "rezervat", that means it must update itself in the database. Unfortunatelly, I am new in VB.net and I don't know how to do it exactly. I've attached the photo and the code. Thanks in advance!

Imports System.Data.Odbc
Public Class Form4
    Public conexiune As New OdbcConnection()
    Dim comanda As New OdbcCommand()

    Private Sub SplitContainer1_SplitterMoved(ByVal sender As System.Object, ByVal e As System.Windows.Forms.SplitterEventArgs) Handles SplitContainer1.SplitterMoved

    End Sub

    Private Sub Form4_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        'TODO: This line of code loads data into the 'PostgresDataSet.dateimprumutrestituire' table. You can move, or remove it, as needed.
        Me.DateimprumutrestituireTableAdapter.Fill(Me.PostgresDataSet.dateimprumutrestituire)
        conexiune.ConnectionString = "Driver={PostgreSQL ANSI};database=postgres;server=localhost;port=5432;uid=postgres;pwd=postgres;sslmode=disable;readonly=0;protocol=7.4;fakeoidindex=0;showoidcolumn=0;rowversioning=0;showsystemtables=0;fetch=100;socket=4096;unknownsizes=0;maxvarcharsize=255;maxlongvarcharsize=8190;debug=0;commlog=0;optimizer=0;ksqo=1;usedeclarefetch=0;textaslongvarchar=1;unknownsaslongvarchar=0;boolsaschar=1;parse=0;cancelasfreestmt=0;extrasystableprefixes=dd_;lfconversion=1;updatablecursors=1;disallowpremature=0;trueisminus1=0;bi=0;byteaaslongvarbinary=0;useserversideprepare=0;lowercaseidentifier=0;xaopt=1"
        conexiune.Open()

    End Sub

    Private Sub btnCauta_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnCauta.Click
        Me.DateimprumutrestituireBindingSource.Filter = "autor = '" & Me.txtCuvinteCheie.Text & " ' "
    End Sub

    Private Sub btnInchide_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnInchide.Click
        Me.Close()
    End Sub

    Private Sub btnAdauga_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnAdauga.Click
        MsgBox("Cartea cu cota " + CotaLabel1.Text + " a fost rezervata cu succes!")
        Try
            comanda.CommandText = "UPDATE dateimprumutrestituire SET disponibilitate='rezervat'"
            comanda.Connection = Me.conexiune
            comanda.ExecuteNonQuery()
        Catch eroare As Odbc.OdbcException
            MessageBox.Show("Cartea nu a putut fi rezervata" & Chr(13) & eroare.Message)

        End Try

    End Sub
End Class

[imgnothumb]http://bytes.com/attachments/attachment/5188d1306621527/prt.jpg[/imgnothumb]