Help passing web control id to a sub routine

I am trying to passing a panel id to to a sub routine with a onclick on a button with VB.Net

I have several panels that I want to make visible or invisible, I want to create one sub to the same routine.

ex.


sub runIt(a as object, e as eventargs, pnlName as string)
if a.text="+" then
pnlName.visible=true
' pnlTravel.visible=true This works fine
a.text="-"
else
pnlName.visible=false
' pnlTravel.visible=false this works fine
a.text="+"
end if
End sub


<asp:Button id="btnAdd2" onclick="runIt('pnlTravel')" runat="server" Font-Size="XX-Small" BorderStyle="Solid" Text="+" BackColor="White" BorderColor="DarkGray" />
<asp:Panel id="pnlTravel" runat="server">My code goes here</asp:Panel>

Please help I'm new to .NET

James

Here is an example i wrote, which sets the first control to visible and the second control to invisible:

VB Code:

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        ShowPanel("Panel2", "Panel1")
    End Sub
 
    Function ShowPanel(ByVal strPanel As String, ByVal strHide As String)
        Dim x As Control
        Dim myFrm As Control
        Label1.Text = Panel1.Parent.ID()
        For Each myFrm In Me.Controls
'Find the Form
            If myFrm.ID = "Form1" Then
                Exit For
            End If
        Next
        For Each x In myFrm.Controls
            Select Case LCase(x.ID)
                Case LCase(strPanel)
                    x.Visible = True
 
                Case LCase(strHide)
                    x.Visible = False
            End Select
        Next
    End Function
 
    Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
        ShowPanel("Panel1", "Panel2")
    End Subp