Gemmer ikke data

JEg sidder og leger med windows form programming i VS2008, har lavet en lille "dims" der gemmer data in en database lokalt (MyData.mdf) og viser det så i en listbox.

Men når jeg åbner programmet igen har den ikke gemt noget, den gemmer kun når programmet er åbent, derefter er alt væk?

Har vedhæftet filen:
Imports System.Data
Imports System.Data.SqlClient
Imports System.Data.OleDb

Public Class Form1
    ' A data set for use by the form
    Dim mydataset As DataSet = New DataSet()

    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        ' Configure the connection
        Dim strconn = "Data Source=.\SQLExpress;Integrated Security=true;AttachDbFilename=minsti.....App_Data\MyData.mdf;User Instance=true;"
        Dim conn As SqlConnection = New SqlConnection(strconn)
        ' Create the adapter from the connection
        Dim adapter As SqlDataAdapter = New SqlDataAdapter(conn.CreateCommand())
        adapter.SelectCommand.CommandText = "select * from BrowserData"
        ' Fill the data set with the Customers table
        adapter.Fill(mydataset)

        ' Populate list box
        PopulateListBox()
    End Sub

    Sub PopulateListBox()
        ' Clear the list box
        ListBox.Items.Clear()

        ' Enumerate cached data
        Dim row As DataRow
        For Each row In mydataset.Tables(0).Rows
            Dim item As String = row("name") & ", " & row("bid")
            ListBox.Items.Add(item)
        Next


    End Sub

    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        ' Ask table for an empty DataRow
        Dim row As DataRow = mydataset.Tables(0).NewRow()


        ' Fill DataRow with column data
        row("name") = TextBox1.Text
        row("date") = DateAndTime.Now


        ' Add DataRow to the table
        mydataset.Tables(0).Rows.Add(row)

        ' Update list box
        PopulateListBox()
    End Sub

End Class