// passage time
var pass= 168;

// display content
var content = '<img src="http://wom.osirase.jp/contents/images/blog_new2.gif" alt="New" />';

var currentDate = new Date();
var spans = document.getElementsByTagName('span');
for (i = 0; i < spans.length; i++) {
	if(spans[i].getAttribute('class') == 'new' ||
	spans[i].getAttribute('className') == 'new') {
	time = spans[i].childNodes[0].nodeValue.split(":");
	var entryDate = new Date(time[0], time[1]-1, time[2], time[3], time[4], time[5]);
	var now = (entryDate.getTime() - currentDate.getTime())/(60*60*1000);
	now = Math.ceil(now);
	if(-now <= pass) {
	spans[i].innerHTML = content;
	spans[i].style.display = 'inline';
	}
	}
}