function slide_next() {
	slides_next = slides_current + 1;
	
	if (slides_next > slides_num) {
		slides_next = 1;
	}
		
	current_slide = document.getElementById('slide_' + slides_current);
	
	if (current_slide != null) {
		current_slide.style.display = "none";
	
	}
	
	next_slide = document.getElementById('slide_' + slides_next);
	
	if (next_slide != null) {
		next_slide.style.display = "block";
	}
	
	slides_current = slides_next;

}

function slide_prev() {
	slides_prev = slides_current - 1;
	
	if (slides_prev < 1) {
		slides_prev = slides_num;
	}
	
	current_slide = document.getElementById('slide_' + slides_current);
	
	if (current_slide != null) {
		current_slide.style.display = "none";
		
	}
	
	prev_slide = document.getElementById('slide_' + slides_prev);
	
	if (prev_slide != null) {
		prev_slide.style.display = "block";
	}
	
	slides_current = slides_prev;

}