Swapping two numbers

Write a program swapping two numbers.

#include <iostream.h>

#include <conio.h>

void main()

{

int a,b;

cout<<"Ener value for a: ";

cin>>a;

cout<<"Enter value for b: ";

cin>>b;

a=a+b;

b=a-b;

a=a-b;

cout<<"Value of a: "<<a<<"\n""Value of b: "<<b;

getch();

}