Change the comparison statement:
Code:
var alarm_timer = 0;
while(1)
{
if(alarm_timer >= 5) // after 5 seconds
{ 
beep();
}
alarm_timer += time_step / 16;
wait(1);
}

This way, it is still caught if it skips 5 altogether.

Jibb

Formerly known as JulzMighty.
I made KarBOOM!