swap function
	
	
	1. The method:
	
	To swap two values "value1" and "value2", we need to create the third 
	temporary one "tempo" , to put within the first one while changing the 
	two variables, as follows:

	tempo = value1 ;
	value1     = value2 ;
	value2     = tempo ;


	2. Example:

	#include <stdio.h>

	int main()
	{  
	int value1, value2, tempo ;
	
	/* Scaning the two values */

	printf("Enter two integers\n");
	scanf ("%d%d", &value1, &value2);

	/* Displaying the two values*/

	printf("Before swapping, value1 = %d,  value2 = %d\n",
		 value1, value2);
	
	/* Swapping the two values */
	
	tempo = value1 ;
	value1     = value2 ;
	value2     = tempo ;
	

	/* Displaying the swapped values*/

	printf("After swapping, value1 = %d,  value2 = %d\n",
		 value1, value2);
		 return 0;
	}