C++ program which reads a lowercase letter and print equivalent uppercase letter

#include<iostream.h>
void main()
{

  clrscr();
  char s1,s2;
  cout<<"Enter The lower case charecter\n";
  cin>>s1;
  s2=s1-32;
  cout<<"\n upper case letter of " <<s1<<" is "<<s2;
   getch();
}