  Glass-like materials are nonequilibrium systems where the relaxation time may
exceed reasonable time scales of observations. In the present paper a dynamic
percolation model is introduced in order to explain the principal properties of
glass-like materials near the dynamic transition. Here, contrary to
conventional percolation problems, clusters are groups of particles dynamically
correlated. Introducing a size dependent relaxation time and the scaling
hypothesis for the distribution of dynamically correlated clusters the two step
relaxation predicted by the mode coupling theory and observed in experiments is
obtained.
