function switch_layer(i) {
  var e = xoopsGetElementById('sub'+i);
  if (e.style.display == '') e.style.display = 'none';
  e.style.display = (e.style.display == 'none') ? 'block' : 'none';

  var exp = new Date(); 
  exp.setTime(exp.getTime() + (30*24*60*60*1000));
  SetCookie('menu', i, e.style.display, exp);
}
  
function SetCookie(name, element, value, expires) {
  if (!expires) expires = new Date();
  var cookie = '|'+GetCookie(name);
  cookie = cookie.replace('|'+element+':b', '');
  cookie = cookie.replace('|'+element+':n', '');
  cookie = cookie.substr(1, cookie.length-1);
  if (cookie.length != 0) cookie = cookie+'|';
  cookie = cookie+element+':'+value.substr(0, 1);
  
  document.cookie = name + "=" + escape(cookie) + "; expires=" + expires.toGMTString() +  "; path=/";
}

function GetCookie(name) {
  cookie_name = name + "=";
  cookie_length = document.cookie.length;
  cookie_begin = 0;
    
  while (cookie_begin < cookie_length) {
    value_begin = cookie_begin + cookie_name.length;
    if (document.cookie.substring(cookie_begin, value_begin) == cookie_name) {
      var value_end = document.cookie.indexOf (";", value_begin);
      if (value_end == -1) value_end = cookie_length;
      return unescape(document.cookie.substring(value_begin, value_end));
    }
    cookie_begin = document.cookie.indexOf(" ", cookie_begin) + 1;
    if (cookie_begin == 0) break;
  }
  return "";
}

function GetMenuState(element) {
  cookie = GetCookie('menu');
  if (cookie.length == 0) {
  	return 'none';
  } else {
  	cookie = '|'+cookie;
    value_begin = cookie.indexOf('|'+element+':');
  
    if (value_begin == -1) {
      return 'none';
    } else {
  	  value_begin += 3
      value = cookie.substr(value_begin, 1);
  	  value = (value == 'b') ? 'block' : 'none';
  	  return value;
    }
  }
}