COMO VERIFICAR SE O FORM JA ESTA ABERTO?

     'verifica se o forme já esta aberto
[c]        Private Function verificaForm(ByVal v_form As String) As Boolean

        Dim v_forms As Integer
        v_forms = Me.MdiChildren.Length - 1
        If v_forms < 0 Then
            Return False
        End If
        Do While v_forms >= 0
            If Me.MdiChildren(v_forms).Name.ToString = v_form Then
                Me.ActiveMdiChild.Name = v_form
                Return True
            End If
            v_forms = v_forms - 1
        Loop
        Return False
    End Function

 Dim Frm As New Nome_do_Formulário
        If Not verificaForm("Nome_do_Formulário") Then
            Frm.MdiParent = Me
            Me.Cursor = System.Windows.Forms.Cursors.WaitCursor
            Frm.Show()
            Me.Cursor = System.Windows.Forms.Cursors.Default
        End If