A palindromic number reads the same both ways. 


The largest palindrome made from the product of two 2-digit numbers is 9009 = 91 × 99.


Write a function that is called this way:


>> n = palin_product(dig,lim);



The function returns the largest palindrome smaller than lim that is the product of two dig digit numbers. 


If no such number exists, the function returns 0.