function change(){
day = new Date();
hour = day.getHours();
if (hour < 6) { document.piasimage.src = 'images/piasimage_index2.jpg' }
else
if (hour < 18) { document.piasimage.src = 'images/piasimage_index.jpg' }
else
if (hour < 24) { document.piasimage.src = 'images/piasimage_index2.jpg' }
setTimeout("change()",1000);
}