Fibonacci number and recursive function

i was looking for questions on while loops when i came across a problem that said write a program that displays fibonacci numbers
and the code that i wrote works just fine

Code:

int x1=1;
int x2=1;
int x3;
int x;
cout<<"please enter the number "<<endl;
cin>>x;
cout<<x1<<endl<<x2<<endl;
while (x2<x)
{
    x3=x1+x2;
    x1=x2;
   x2=x3;
  cout<<x1<<endl<<x2<<endl;

}

but the second part of the question says write another program but this time using recursive funtion
can any body please explain that to me and also how can i change my program to become a recursive function
i can write this as a seprate funtion
but how to find the terminating if function and how to approach this problem using recursive I have an exam coming up please help as soon as possible

 

i am using visual .net 2003 compiler and windows xp professsional