var dateObj = new Date();
var h = dateObj.getHours();
if(h==5){
document.write('<link rel="stylesheet" type="text/css" href="common/css/rising.css" media="all" />');
}else if(h==18){
document.write('<link rel="stylesheet" type="text/css" href="common/css/evening.css" media="all" />');
}else if(h>5 && h<12){
document.write('<link rel="stylesheet" type="text/css" href="common/css/morning.css" media="all" />');
}else if(h>=12 && h<19){
document.write('<link rel="stylesheet" type="text/css" href="common/css/afternoon.css" media="all" />');
}else{
document.write('<link rel="stylesheet" type="text/css" href="common/css/midnight.css" media="all" />');
}