day=new Date()     //..get the date

x=day.getHours()    //..get the hour

if(x>=6 && x<9) {

   document.write('<style type="text/css">#headercontent {background-image: url(_images/header_morning.jpg)}"></style>')

} else

if(x>=9 && x<18) {

   document.write('<style type="text/css">#headercontent {background-image: url(_images/header_day.jpg)}</style>')

} else

if(x>=18 && x<21) {

   document.write('<style type="text/css">#headercontent {background-image: url(_images/header_evening.jpg)}</style>')

} else

if (x>=21 && x<24) {

   document.write('<style type="text/css">#headercontent {background-image: url(_images/header_night.jpg)}</style>')

}else
	
	document.write('<style type="text/css">#headercontent {background-image: url(_images/header_night.jpg)}</style>')