var base_class = "istate";
var setting = getCookie("foldersetting");
if(setting == "") setting = 0;

function get_parent(f) {
	while(f.parentNode != null) {
		if(f.parentNode.className.indexOf(base_class) != -1) {
			return f.parentNode;
		}
		f = f.parentNode;
	}
	return null;
}

function toggle_folder(f, id) {

	var parent = this.get_parent(f);
	var shift = id - 1;
	var new_setting = setting ^ (1 << shift);
	
	if(parent != null) {
		if(parent.className.indexOf("opened") != -1) {
			parent.className = base_class + " closed";
		} else {
			parent.className = base_class + " opened";
		}
	}
	setting = new_setting;
	setCookie("foldersetting", new_setting, 15);
	
	return true;
}

function setCookie(c_name,value,expiredays) {
	var exdate=new Date();
	exdate.setDate(exdate.getDate()+expiredays);
	document.cookie=c_name+ "=" +escape(value)+
	((expiredays==null) ? "" : ";expires="+exdate.toGMTString());
}

function getCookie(c_name) {
	if (document.cookie.length>0) {
		c_start=document.cookie.indexOf(c_name + "=");
	  if (c_start!=-1) { 
			c_start=c_start + c_name.length+1; 
	    c_end=document.cookie.indexOf(";",c_start);
			if (c_end==-1) c_end=document.cookie.length;
	    return unescape(document.cookie.substring(c_start,c_end));
    } 
  }
	return "";
}