var slides_current = 1;

function start_slideshow() {
	cmd = 'next_slide()';
	setTimeout(cmd, 2000);

}

function next_slide() {
	var slides_next = slides_current + 1;
	
	if (slides_next > slides_num) {
		slides_next = 1;
	}
	
	current_div = document.getElementById('slide_' + slides_current);
	current_div.style.display = "none";
	
	next_div = document.getElementById('slide_' + slides_next);
	next_div.style.display = "block";
	
	slides_current = slides_next;
	
	cmd = 'next_slide()';
	setTimeout(cmd, 3000);
}