To Add Own Header File in C++

"Nice One Program"

#include<iostream.h>
#include<conio.h>    
#include"myfile.h"

void main()                
{         clrscr();
int a=10,b=20;
int c=sum(a,b);                 //no prototype now create new file with extension .h
cout<<"Sum="<<c;      //again error now include file using ""

getch();
}


FILE WITH .H Exntension Will Have

int sum(int x,int y)
{
return (x+y);
}