Data entered in Access table via VB seem to work, but missing next time file is opened.

I have used MS Access 2013 to create a db-file with some data. I have then written some code in VB.NET that opens and access the data. I can create new records, and I can page through them back and forth and all seems fine. But when I run my program again, the data I entered has gone missing. I use

    Private Function storeData(ByVal mySql As String) As Boolean
        Dim ret As Boolean = False
        Dim ac As New System.Data.OleDb.OleDbConnection("Provider=Microsoft.ACE.OLEDB.12.0;Data Source=" & myPath)
        Try
            Using ac
                Dim myCommand = New System.Data.OleDb.OleDbCommand(mySql, ac)
                myCommand.Connection.Open()
                myCommand.ExecuteNonQuery()
                myCommand.Connection.Close()
            End Using

            ret = True
        Catch ex As Exception
            MsgBox("There is something wrong." & _
                   vbNewLine & ex.ToString, MsgBoxStyle.Exclamation, "SQL Error")
        End Try
        Return ret
    End Function

Select allOpen in new window

The SQL command looks something like this:

Insert into NAD(Name,Address,Postnumber,Telefonnumber,Epostaddress,Webpage) values('Thor','Oslo','0575','999 88 777','epost@epost.no','www.web.com');

Select allOpen in new window

and seem to work fine, and when I browse through the table using my program after having entered a new record, I can see the new records. But when I close the program and reopens it, or query the DB from outside, the newly entered data have disappeared. What am I missing? Do I need som kind of file save or commit or something?