Detect when derma pannel is open?

[MrTHC]

I'm using this third person script I found on here and was wondering if there is any way to detect when the point shop window is in view? I want it to force the client to first person if the point shop window is in view so their hats don't bug out on the preview window in case they are in third person. Would using something like "gui.IsGameUIVisible( )" work for this?

The thirdperson script:

if( CLIENT ) then

	function ThirdPersonUmsg( data )
		if( LocalPlayer().ThirdPerson == nil ) then
			LocalPlayer().ThirdPerson = true;
		else
			LocalPlayer().ThirdPerson = !LocalPlayer().ThirdPerson;
		end;	
	end;
	usermessage.Hook( "ThirdPerson", ThirdPersonUmsg );
	
	function ThirdPerson( ply, pos, ang, fov )
		if( LocalPlayer().ThirdPerson ) then
			local view = {};
			local dist = 100;
			local trace = {};
			
			trace.start = pos;
			trace.endpos = pos - ( ang:Forward() * dist );
			trace.filter = LocalPlayer();
			local trace = util.TraceLine( trace );
			if( trace.HitPos:Distance( pos ) < dist - 10 ) then
				dist = trace.HitPos:Distance( pos ) - 10;
			end;
			view.origin = pos - ( ang:Forward() * dist );
			view.angles = ang;
			view.fov = fov;
			
			return view;
		end;
	end;
	hook.Add( "CalcView", "ThirdPerson", ThirdPerson );
	
	function ThirdPersonSDLP()
		if( LocalPlayer().ThirdPerson ) then
			return true;
		end;
	end;
	hook.Add( "ShouldDrawLocalPlayer", "ThirdPersonSDLP", ThirdPersonSDLP );


else


	function ToggleThirdPerson( ply )
		umsg.Start( "ThirdPerson", ply );
		umsg.End();
	end;
	hook.Add( "ShowTeam", "ToggleThirdPerson", ToggleThirdPerson );
	
end;

anyone have any ideas?