function createCookie(name,value,days) {
   if (days) {
      var date = new Date();
      date.setTime(date.getTime()+(days*24*60*60*1000));
      var expires = "; expires="+date.toGMTString();
   }
   else var expires = "";
   document.cookie = name+"="+value+expires+"; path=/";
}

function readCookie(name) {
   var nameEQ = name + "=";
   var ca = document.cookie.split(';');
   for(var i=0;i < ca.length;i++) {
      var c = ca[i];
      while (c.charAt(0)==' ') c = c.substring(1,c.length);
      if (c.indexOf(nameEQ) == 0) return c.substring(nameEQ.length,c.length);
   }
   return null;
}

function eraseCookie(name) {
   createCookie(name,"",-1);
}

function updateSelected(cell) {
   var selected = readCookie('SELECTED');
   if (selected) {
      var e = document.getElementById(cell);
      e.innerHTML = selected;
   }
}

function addProperty(id) {
   var selected = readCookie('SELECTED');
   var properties = readCookie('PROPERTIES');
   selected++;
   createCookie('SELECTED',selected,7);
   if (properties) {
      properties = properties + "," + id;
   } else {
      properties = id;
   }
   createCookie('PROPERTIES',properties,7);
   updateSelected('selected');
}