NUM_POSSESS_SLOTS = 2;
 POSSESS_CANCEL_SLOT = 2;
 
 function PossessBar_Update ()
 	if ( not MainMenuBar.busy and not UnitHasVehicleUI("player") ) then	--Don't change while we're animating out MainMenuBar for vehicle UI
 		local needFrameMgrUpdate = false;
 		if ( IsPossessBarVisible() ) then
 			if ( not PossessBarFrame:IsShown() ) then
 				PossessBarFrame:Show();
 				needFrameMgrUpdate = true;
 			end
 			PossessBar_UpdateState();
 		elseif ( PossessBarFrame:IsShown() ) then
 			PossessBarFrame:Hide();
 			needFrameMgrUpdate = true;
 		end
 		
 		if ( needFrameMgrUpdate ) then
 			UIParent_ManageFramePositions();
 		end
 	end
 end
 
 function PossessBar_UpdateState ()
 	local texture, name, enabled;
 	local button, background, icon, cooldown;
 
 	for i=1, NUM_POSSESS_SLOTS do
 		-- Possess Icon
 		button = _G["PossessButton"..i];
 		background = _G["PossessBackground"..i];
 		icon = _G["PossessButton"..i.."Icon"];
 		texture, name, enabled = GetPossessInfo(i);
 		icon:SetTexture(texture);
 
 		--Cooldown stuffs
 		cooldown = _G["PossessButton"..i.."Cooldown"];
 		cooldown:Hide();
 
-		button:SetChecked(nil);
+		button:SetChecked(false);
 		icon:SetVertexColor(1.0, 1.0, 1.0);
 
 		if ( enabled ) then
 			button:Show();
 			background:Show();
 		else
 			button:Hide();
 			background:Hide();
 		end
 	end
 end
 
 function PossessButton_OnClick (self)
-	self:SetChecked(nil);
+	self:SetChecked(false);
 
 	local id = self:GetID();
 	if ( id == POSSESS_CANCEL_SLOT ) then
 		if ( UnitControllingVehicle("player") and CanExitVehicle() ) then
 			VehicleExit();
 		else
 			local texture, name = GetPossessInfo(id);
 			CancelUnitBuff("player", name);
 		end
 	end
 end
 
 function PossessButton_OnEnter (self)
 	local id = self:GetID();
 
 	if ( GetCVar("UberTooltips") == "1" ) then
 		GameTooltip_SetDefaultAnchor(GameTooltip, self);
 	else
 		GameTooltip:SetOwner(self, "ANCHOR_RIGHT");
 	end
 
 	if ( id == POSSESS_CANCEL_SLOT ) then
 		GameTooltip:SetText(CANCEL);
 	else
 		GameTooltip:SetPossession(id);
 	end
 end