How to allocate memory for a multidimensional array dynamically?

Many times we need to allocate memory for a multidimensional array dynamically. Because of complexity of pointers many find this difficult. Following program allocates memory for a 3 x 3 array dynamically, copies contents of a 3 x 3 array in it and prints the contents using the pointer.

#include <iostream.h>
int a[ ][3] = { 1, 2, 3, 
                     4, 5, 6, 
                     7, 8, 9 
                  } ; 

void main( )

{       int **p ; 
      p = new int *[3] ; 
      for ( int i = 0 ; i < 3 ; i++ ) 
               p[i] = new int[3] ; 
      for ( i = 0 ; i < 3 ; i++ ) 
         for ( int j = 0 ; j < 3 ; j++ ) 
              p[i][j] = a[i][j] ; 
      for ( i = 0 ; i < 3 ; i++ )

      { 
         for ( j = 0 ; j < 3 ; j++ ) 
         cout << p[i][j] ; 
         cout << "\n" ; 
      } 
}