答:js的月份就是0~11,所以 start.getMonth()=实际月份-12. 日期减去天数等于第二个日期 
<script language=javascript> 
function cc(dd,dadd) 

//可以加上错误处理 
var a = new Date(dd) 
a = a.valueOf() 
a = a - dadd * 24 * 60 * 60 * 1000 
a = new Date(a) 
alert(a.getFullYear() + "年" + (a.getMonth() + 1) + "月" + a.getDate() + "日") 

cc("12/23/2002",2) 
</script> 三,可以吧,不太确定<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
"http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<title>无标题文档</title>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312">
<style type="text/css"> 
{
 .showTD {color: #003366; } 
 .hiddenTD {display:none; } 
 .onFocue  {color: #CC66FF;}
 .offFocue {color:#003366;}
}
#floater {
   LEFT: 445px; POSITION: absolute; TOP: 15px; VISIBILITY: visible; WIDTH: 125px; Z-INDEX: 10}
</STYLE>
</head><body><object classid="clsid:0002E510-0000-0000-C000-000000000046" id="Spreadsheet1" width="676" height="388">
 <param name="HTMLURL" value>
 <param name="HTMLData" value="">
 <param name="DataType" value="HTMLDATA">
 <param name="AutoFit" value="0">
 <param name="DisplayColHeaders" value="-1">
 <param name="DisplayGridlines" value="-1">
 <param name="DisplayHorizontalScrollBar" value="-1">
 <param name="DisplayRowHeaders" value="-1">
 <param name="DisplayTitleBar" value="-1">
 <param name="DisplayToolbar" value="-1">
 <param name="DisplayVerticalScrollBar" value="-1">
 <param name="EnableAutoCalculate" value="-1">
 <param name="EnableEvents" value="-1">
 <param name="MoveAfterReturn" value="-1">
 <param name="MoveAfterReturnDirection" value="0">
 <param name="RightToLeft" value="0">
 <param name="ViewableRange" value="1:65536">
</object>
<div class="hiddenTD" id="tablers">
<table width=95% align=center border=1 cellspacing=0 cellpadding=0>
 <tr>
   <td>客户名称A</td>
   <td>客户名称B</td>
   <td>客户名称C</td>
   <td>客户名称D</td>
   <tr>
   <td>abc</td>
   <td>def</td>    <td>111</td>    <td>222</td>  <tr>
   <td>ddd</td>
   <td>dfdf</td>
   <td>ddd</td>
   <td>ddd</td>
</table>
</div>
<script language="javascript">
 Spreadsheet1.HTMLData = tablers.innerHTML ;
</script>
</body>
</html>