using return by reference C++

Prog 13: Write a program to find max value using return by reference.

#include<iostream.h>

#include<conio.h>

int &max(int *,int *);

int &max(int &a,int &b)

{

if(a>b)

return a;

else

return b;

}

void main()

{

int m,n;

clrscr();

cout<<"enter the value of m:";

cin>>m;

cout<<"enter the value of n:";

cin>>n; 
max(m,n)=100; 
cout<<"m="<<m<<endl;
cout<<"n="<<n<<endl;

getch();

}

Output:

enter the value of m:3 enter the value of n:5 m=3

n=100