How to if click the button in the ribbon it will show up in tabcontrol

[icax]

I have a form,
In the form there is panel 1 and panel 2,
In panel1, i put the devcompone ribbon, and i made menu1 and menu2 buttons

How to click on menu1 the form will appear in panel2

I use devcomponen.dotnetbar2.dll for ribbon
And mditabstip.dll for tabcontrol

Public Class Form1
    Sub OPEN_FORM(ByVal FR As Form)
        For Each F As Form In Me.MdiChildren
            If F.Name = FR.Name Then
                MsgBox("FORM IS OPEN...")
                Exit Sub
            End If
        Next
        FR.MdiParent = Me
        FR.Show()
    End Sub
    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load

    End Sub

    Private Sub ButtonItem2_Click(sender As Object, e As EventArgs) Handles ButtonItem2.Click
        OPEN_FORM(MENU1)
    End Sub

    Private Sub ButtonItem3_Click(sender As Object, e As EventArgs) Handles ButtonItem3.Click
        OPEN_FORM(MENU2)
    End Sub
End Class

How To Make The Form When Enlarged Remains Within Panel2

Please help

Thanks