javascript日期相减

<SCRIPT   LANGUAGE="JavaScript">   
  <!--   
    
  var   strDate1   =   "2004-09-17   03:03:00.0";   
  var   strDate2   =   "2004-09-17   04:05:00.0";   
  strDate1=strDate1.substring(0,strDate1.lastIndexOf(".")).replace(/-/g,"/");   
  strDate2=strDate2.substring(0,strDate2.lastIndexOf(".")).replace(/-/g,"/");   
  var   date1   =   Date.parse(strDate1);   
  var   date2   =   Date.parse(strDate2);   
  alert("strDate2与strDate1相差"+(date2-date1)/(60*60*1000)+"小时")  
  alert("strDate2与strDate1相差"+(date2-date1)/(60*60*1000*24)+"天")    
  //-->   
  </SCRIPT>