// passage time 
var pass = 72; 

// display content 
//var content = 'New'; 
var content = '<img src="http://animehack.jp/img/common/new.gif" style="vertical-align: middle" />';

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].innerHTML.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'; 
        } 
    } 
}