Derma Menu - Change class to default class(citizen) when this button is pressed

Not sure what I’m doing. Basically, the 2nd button should change the players class to the default class which is citizen if pressed. It’s not giving me the output I want. This is for darkrp.
Code:
[lua]
function MyCoolMenu()
local Frame = vgui.Create( “DFrame” )
Frame:SetTitle( “Make a person a cop” )
Frame:SetSize( 300, 500 )
Frame:Center()
Frame:MakePopup()

local Button = vgui.Create( “DButton”, Frame )
Button:SetText( “test1” )
Button:SetTextColor( Color( 255, 255, 255 ) )
Button:SetPos( 100, 50 )
Button:SetSize( 100, 30 )
Button.Paint = function( self, w, h )
draw.RoundedBox( 0, 0, 0, w, h, Color( 41, 128, 185, 250 ) ) – Draw a blue button
end
Button.DoClick = function( ply, team )
ply:changeTeam(GAMEMODE.DefaultTeam, true)
end

local Button = vgui.Create( “DButton”, Frame )
Button:SetText( “test2” )
Button:SetTextColor( Color( 255, 255, 255 ) )
Button:SetPos( 100, 100 )
Button:SetSize( 100, 30 )
Button.Paint = function( self, w, h )
draw.RoundedBox( 0, 0, 0, w, h, Color( 41, 128, 185, 250 ) ) – Draw a blue button
end
Button.DoClick = function(ply)

ply:changeTeam(GAMEMODE.DefaultTeam, true)
end
end
concommand.Add( “open_coolmenu”, MyCoolMenu )
[/lua]

Console Error:
[lua]
[ERROR] gamemodes/darkrp/gamemode/cl_init.lua:56: attempt to call method ‘changeTeam’ (a nil value)

  1. DoClick - gamemodes/darkrp/gamemode/cl_init.lua:56
  2. unknown - lua/vgui/dlabel.lua:218

[/lua]

ChangeTeam is probably a serverside only function, whereas derma menus are clientside - look into using the net library