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

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

if(x>=0 && x<3) {

   document.write('<style type="text/css">body{background: url(images/avond.png); background-repeat:no-repeat; background-position:top center;}"></style>')

} else

if(x>=3 && x<12) {

   document.write('<style type="text/css">body{background: url(images/ochtend.png); background-repeat:no-repeat; background-position:top center;}</style>')

} else

if(x>=12 && x<17) {

   document.write('<style type="text/css">body{background: url(images/middag.png); background-repeat:no-repeat; background-position:top center;}</style>')

} else

if (x>=17 && x<24) {

   document.write('<style type="text/css">body{background: url(images/avond.png); background-repeat:no-repeat; background-position:top center;}</style>')

}