var timedate= new Date("May 1,2010");   
   var times= "2010年上海世博会";   
   var now = new Date();   
   var date = timedate.getTime() - now.getTime();    
   var time = Math.floor(date / (1000 * 60 * 60 * 24)+1); 
   var day = -time
   if (time > 0) document.write( "<span class=timet>距"+times+"还有 <span class=timed>"+time +"</span> 天</span>")   
   else if (time <=3)   
   document.write( "<span class=timet>"+times+"已开幕 <span class=timed>"+(day+1) +"</span> 天</span>")