// JavaScript Document

document.getElementsByClassName = function(cl) {
var retnode = [];
var myclass = new RegExp('\\b'+cl+'\\b');
var elem = this.getElementsByTagName('*');
for (var i = 0; i < elem.length; i++) {
var classes = elem[i].className;
if (myclass.test(classes)) retnode.push(elem[i]);
}
return retnode;
}; 

function next_addon(id){
	var start = id-2;
	show_addons(start, id);
}

function prev_addon(id){
	var end = id+2;
	show_addons(id, end);
}

function show_addons(start_id, end_id){

	
	var addons = document.getElementsByClassName('addon');

	show_left_arrow(start_id);
	show_right_arrow(end_id, addons.length);
	if(start_id>0){
		for(var i=0;i<start_id;i++){
			var my_addon = document.getElementById('addon_' + i);
			if(my_addon!=null){
				my_addon.className = 'addon hide';
			}
		}
	}
	if(end_id<addons.length){
		for(var i=end_id+1;i<addons.length;i++){
			var my_addon = document.getElementById('addon_' + i);
			if(my_addon!=null){
				my_addon.className = 'addon hide';
			}
		}
	}
	for(var i =start_id;i<=end_id;i++){
		var my_addon = document.getElementById('addon_' + i);
		if(my_addon!=null){
			my_addon.className = 'addon';
		}
	}
	
}

function show_left_arrow(id){
	var e = document.getElementById('left_arrow');	
	if(id<=0){
		e.innerHTML = '';
	}else{
		var my_id = id-1;
		e.innerHTML = '<a href="javascript:prev_addon(' + my_id + ')"><img src="assets/images/misc/arrow_left.gif" width="15" height="14" /></a>';
	}
	
}
function show_right_arrow(id, count){
	var e = document.getElementById('right_arrow');	
	if(id+1==count){
		e.innerHTML = '';
	}else{
		var my_id = id+1;
		e.innerHTML = '<a href="javascript:next_addon(' + my_id + ')"><img src="assets/images/misc/arrow_right.gif" width="15" height="14" /></a>';
	}
	
}