I am trying to create an association for my vb.net application.

I've got two forms, of which the startup form is called "frmMain" and the other which has a rich textbox that displays results from a file (.tbx) is called "frmResultsViewer"

What I want is that when a person wishes to open a .tbx file on his pc, it should open into "frmResultsViewer".

I am using this code at the moment, but it open into "frmMain". I have placed this code into the "frmResultsViewer" code but still open with the startup form.

Code:
    Public Sub CheckAssociation()
        My.Computer.Registry.ClassesRoot.CreateSubKey(".tbx").SetValue("", "Tiny Toolbox", Microsoft.Win32.RegistryValueKind.String)
        My.Computer.Registry.ClassesRoot.CreateSubKey("Tiny Toolbox\shell\open\command").SetValue("", Application.ExecutablePath & " ""%1"" ", Microsoft.Win32.RegistryValueKind.String)
        My.Computer.Registry.ClassesRoot.CreateSubKey("Tiny Toolbox\DefaultIcon").SetValue("", Application.StartupPath & "\TBX.ico")
    End Sub

FORM LOAD:

Code:
CheckAssociation()

        Dim file As String = Command$()
        If Not file = "" Then
            file = Replace(file, Chr(34), "")
            Me.rtxtResult.LoadFile(file)
        End If