Check if there are mobs alive

[tonibm19]

What's wrong with this?

function HandleCheckCommand( Player )
	local EachEntity = function( Entity )
		if Entity:IsMob() == true then
		       Mobs = Mobs + 1
              end
       end

       local loopPlayer = function ( Player )
              Player:SendMessage( "Killed " .. Mobs .. " mobs." )
              return true
       end
end

It gives me Unknown command