  The Mackey--Glass equation, which was proposed to illustrate nonlinear
phenomena in physiological control systems, is a classical example of a simple
looking time delay system with very complicated behavior. Here we use a novel
approach for chaos control: we prove that with well chosen control parameters,
all solutions of the system can be forced into a domain where the feedback is
monotone, and by the powerful theory of delay differential equations with
monotone feedback we can guarantee that the system is not chaotic any more. We
show that this domain decomposition method is applicable with the most common
control terms. Furthermore, we propose an other chaos control scheme based on
state dependent delays.
