Selective accept in Ada tasking

[paniaguaivan@hotmail.com (Ivan Paniagua)]

I'm a beginner and I have a problem. This code makes my CPU reach
100%:

task body Man_Motor1 is
begin
	while not Fin loop
		select			
			accept Subir;
			null; -- Some actions
		or
			accept Bajar;
			null; -- Some actions
		or
			accept Parar;
			null; -- Some actions
		or
			terminate;
		end select;
	end loop;
end Man_Motor1;

I'm using GNAT 3.14 in a Windows XP platform. If I introduce a delay
before de end loop all it's OK, but what I want is that the task keep
sleeping till it has a call to an entry without consuming a lot of CPU
time.

Can anybody help me?
Thank you very much.