im looking at one of the tutorials, under tutorials circle and line algorithms, vga trainer program, on this site. my question is, what include files do i use to make the c++ program work in his example?i included <iostream>, that fixed one error, but there are 2 more, `round`: undeclared identifier and 'Putpixel' : undeclared identifier. i believe there is a # include file for graphics or something to make it work.thanks