function nightchange()
{
 datetoday = new Date();
 timenow=datetoday.getTime();
 datetoday.setTime(timenow);
 thehour = datetoday.getHours();

 if (thehour >= 22)
  display = "night";
 else if (thehour >= 5)
  display = "day";
 else
  display = "day";

 var thebody =	document.getElementById("body");
 
 thebody.className= display;
 									

}