Simple Chess using Recursive Minimax

Here it is just a try to make a chess playing program. The program runs on a very basic recursive minimax algorithm. So it now plays like a novice chess player, and also subjected to usual problems of recursive minimax. The maximum achievable depth for the minimax tree is 10 here. so at most 5 opponent movements can be foretasted. Also a depth of 4 or 5 is practical considering the time taken for each decision. I am trying to implement it by means of non-recursive minimax algorithm and more constraints on cost benefit analysis of each move to upgrade it to a moderate level chess playing program

Here is the source code