btw, to solve that problem that zwecklos mentioned, in the future you can use something called function prototyping which means you write the function name before main(), and then you can make the function after main. Kinda confusing?...

#include <acknex.h>;

function hello_world();

function main()
{
beep();
hello_world();
}

function hello_world()
{
printf("hello world");
beep();
}

so the function at the top acts like a pointer to the function below main();
function prototyping is familiar in C++.