var current_slide_index = 0;
var slide_count = 0;

function Go(index) {

	var current_slide = document.getElementById("_c" + current_slide_index);
	var slide = document.getElementById("_c" + index);
	current_slide.style.display = "none";
	slide.style.display = "block";
	
	var current = document.getElementById("_n" + current_slide_index);
	current.className = "";
	var pick = document.getElementById("_n" + index);
	pick.className = "current";
	
	current_slide_index = index;
}

function Next() {
	Go((current_slide_index + 1) % slide_count);
}

function Previous() {
	if(current_slide_index - 1 > 0) {
		Go(current_slide_index - 1);
	}
}