<script>
function interact()
{
    var name = prompt("What is your name?");
    alert("Hi, " + name);
}
</script>
<button onclick="interact()">Interact</button>

//An innocuous looking method which will become known as a callback method
//because of the way in which we will invoke it.
int meaningOfLife(void) {
    return 42;
}


//An innocuous looking method which just takes an int and prints it to screen
void Print_A_Number(int a_Number) {
    System.out.print(a_Number);
}

//invoking a method which passes another method as an argument in reaction to an event  (the 'another' method - meaningOfLife - is therefore called a callback method) and the event - main() - is that the program is starting
void main() {
    Print_A_Number(meaningOfLife);
}