pop up menu(DAX Flood Mod)

I am working on a menu that pops up when a player joins to educate the player on how to play. The problem with my menu right now is that I can’t open, close, & then open again the Collapsible Category’s. How do i fix this?

[lua]
function SpawnMenu()
local DermaPanel = vgui.Create( “DFrame” )
DermaPanel:SetPos( 50,50 )
DermaPanel:SetSize( 1000, 700 )
DermaPanel:SetTitle( “Welcome to DAX Flood!” ) // Name of Fram
DermaPanel:SetVisible( true )
DermaPanel:SetDraggable( true )
DermaPanel:ShowCloseButton( true ) //Show the X (Close button) /True/False
DermaPanel:MakePopup()
--------------------------
–About
--------------------------
local AboutCollapsibleCategory = vgui.Create(“DCollapsibleCategory”, DermaPanel)
AboutCollapsibleCategory:SetPos( 25,50 )
AboutCollapsibleCategory:SetSize( 200, 50 ) – Keep the second number at 50
AboutCollapsibleCategory:SetExpanded( 0 ) – Expanded when popped up
AboutCollapsibleCategory:SetLabel( “About DAX Flood” )
--------------------------
–How To Play
--------------------------
local HowCollapsibleCategory = vgui.Create(“DCollapsibleCategory”, DermaPanel)
HowCollapsibleCategory:SetPos( 25,105 )
HowCollapsibleCategory:SetSize( 200, 50 ) – Keep the second number at 50
HowCollapsibleCategory:SetExpanded( 0 ) – Expanded when popped up
HowCollapsibleCategory:SetLabel( “How to Play DAX Flood” )
--------------------------
–About Contents
--------------------------
local AboutSheet = vgui.Create( “DPanel” ) – We create a panel so we can draw stuff on; if we use the frame, it comes up transparent for some reason
AboutSheet:SetPos( 10, 10 )
AboutSheet:SetSize( 200, 200 )
AboutSheet.Paint = function()
local OurStringThing = “About” – This was a pain in the ass to figure out; this gets the name of the option chosen
surface.SetFont( “default” )
surface.SetTextColor( 255, 255, 255, 255 )
surface.SetTextPos( 50, 50 )
surface.DrawText( OurStringThing ) – Draws the text
end
AboutCollapsibleCategory:SetContents( AboutSheet )
--------------------------
–How To Play Contents
--------------------------
local HowSheet = vgui.Create( “DPanel” ) – We create a panel so we can draw stuff on; if we use the frame, it comes up transparent for some reason
HowSheet:SetPos( 10, 10 )
HowSheet:SetSize( 200, 200 )
HowSheet.Paint = function()
local OurStringThing = “How to Play” – This was a pain in the ass to figure out; this gets the name of the option chosen
surface.SetFont( “default” )
surface.SetTextColor( 255, 255, 255, 255 )
surface.SetTextPos( 50, 50 )
surface.DrawText( OurStringThing ) – Draws the text
end
HowCollapsibleCategory:SetContents( HowSheet )

local DermaButton = vgui.Create( "DButton" )
DermaButton:SetParent( DermaPanel ) // Set parent to our "DermaPanel"
DermaButton:SetText( "Zombie" )
DermaButton:SetPos( 25, 300 )
DermaButton:SetSize( 150, 50 )
DermaButton.DoClick = function ()
	RunConsoleCommand( "kill" ) // What happens when you press the button
end

end
usermessage.Hook( “call_vgui”, SpawnMenu )
[/lua]

anyone know how to use Derma?