javascript方法动态显示前一天与后一天日期时间

脚本语言：

放入客户端代码后

<SCRIPT LANGUAGE="JavaScript">
<!--
  //alert('<%=ntime%>')
  var now = new Date();
  n0=now.getYear()
  y0=now.getMonth()+1
  d0=now.getDate()
  h0="0"+now.getHours();
     m0="0"+now.getMinutes();
     s0="0"+now.getSeconds();
  if(h0>9){h0=now.getHours()}
     if(m0>9){m0=now.getMinutes()}
     if(s0>9){s0=now.getSeconds()}
     document.all.tb1.value = n0+"-"+y0+"-"+d0+" "+h0+":"+m0+":"+s0
  DaysToAdd=0;
function predata_Click()
{
 DaysToAdd=DaysToAdd-1;
 var newdate=new Date(n0,y0,d0,h0,m0,s0);
 var newtimems=newdate.getTime()+(DaysToAdd*24*60*60*1000);
 newdate.setTime(newtimems);
 var xdate=newdate
 var newh="0"+xdate.getHours()
 var newm="0"+xdate.getMinutes()
 var news="0"+xdate.getSeconds()
 if(newh>9){newh=xdate.getHours()}
 if(newm>9){newm=xdate.getMinutes()}
 if(news>9){news=xdate.getSeconds()}
 document.form.tb1.value=xdate.getYear()+"-"+xdate.getMonth()+"-"+xdate.getDate()+" "+newh+":"+newm+":"+news
 frame2.src="./search/yuliangmview.asp"
}
function passdata_Click()
{
 DaysToAdd=DaysToAdd+1;
 var newdate=new Date(n0,y0,d0,h0,m0,s0);
 var newtimems=newdate.getTime()+(DaysToAdd*24*60*60*1000);
 newdate.setTime(newtimems);
 var xdate=newdate
 var newh="0"+xdate.getHours()
 var newm="0"+xdate.getMinutes()
 var news="0"+xdate.getSeconds()
 if(newh>9){newh=xdate.getHours()}
 if(newm>9){newm=xdate.getMinutes()}
 if(news>9){news=xdate.getSeconds()}
 document.form.tb1.value=xdate.getYear()+"-"+xdate.getMonth()+"-"+xdate.getDate()+" "+newh+":"+newm+":"+news
 frame2.src="./search/yuliangmview.asp"
}
//-->
</SCRIPT>

控件代码：

<form name="form" method="post">
<table width="100%">
<tr><td align=center>
<!-- onclick="callpreviousDay()"onclick="callnextDay()" -->
<input type="button" name="predata" value="前一天" style="width: 57px;
            height: 20px" OnClick="predata_Click()" >
<input id="tb1" type="text" ReadOnly="True" style="width: 140px;
            height: 20px;text-align: center;" onclick='showCal()' />
<input type="button" name="passdata" value="后一天" style="width: 57px;
            height: 20px" OnClick="passdata_Click()" >
</tr>
</table>
</form>