How can i determine the contents of a Panel control?

in my app i add some usercontrols inside the panel (one at a time, by clicking a button), but i need to check which usercontrol is currently on the panel, how can i do it?

I found something about checking if contains some control like: panel.contains(label1) but i can't do it when i add an UserControl, what's the correct syntax for that or what can i do?

Public Class Form1

Private Sub Button1_Click(ByVal sender As System.Object, _

ByVal e As System.EventArgs) Handles Button1.Click

' check to see if any of these controls are

' in panel1

MsgBox(InPanel("button1").ToString)

MsgBox(InPanel("button2").ToString)

MsgBox(InPanel("label1").ToString)

MsgBox(InPanel("label2").ToString)

End Sub

Private Function InPanel(ByVal Ctext As String) As Boolean

Dim n As Boolean = False

For Each j As Control In Me.Panel1.Controls

If j.Name.ToUpper = Ctext.ToUpper Then

n = True

End If

Next

Return n

End Function

End Class