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 expires = "";
	
	document.cookie = name+"="+value+expires+"; path=/";
}

function readCookie(name) 
{
  var start = document.cookie.indexOf( name + "=" );
  var len = start + name.length + 1;
  if ( ( !start ) && ( name != document.cookie.substring( 0, name.length ) ) )
  {
    return null;
  }
  if ( start == -1 ) return null;
    
  var end = document.cookie.indexOf( ";", len );
  if ( end == -1 ) 
    end = document.cookie.length;

  return unescape( document.cookie.substring( len, end ) );
}

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