getch() & clrscr() errors

#include <iostream.h>
int main()
{
clrscr();
int x,y,sum;
float average;
cout << "Enter 2 integers : " << endl;
cin>>x>>y;
sum=x+y;
average=sum/2;
cout << "The sum of " << x << " and " << y << " is " << sum << "." << endl;
cout << "The average of " << x << " and " << y << " is " << average << "." << endl;
getch();
}

----------------------------
..\world.cpp:14: error: `getch' was not declared in this scope
..\world.cpp:5: warning: unused variable 'clrscr'
..\world.cpp:14: warning: unused variable 'getch'

getch() and clrscr() are part of conio.h header file. conio.h is used in old MS-DOS compilers to create text user interfaces but not a part of standard c library. So if u r using "MinGW" or "Cygwin" compilers, they wont support these functions.