  This article arose from a series of three lectures given at the Banach
Center, Warsaw, during period of 24 March to 13 April, 2003.
  Morse functions are useful tool in revealing the geometric formation of its
domain manifolds $M$. They define the handle decompositions of $M$ from which
the additive homologies $H_{\ast}(M)$ may be constructed. In these lectures two
further questions were emphasized. (1) How to find a Morse function on a given
manifold? (2) From Morse functions can one derive the multiplicative cohomology
rather than the additive homology?
