如何把下段调用本机时间函数的代码改为调用服务器时间函数？？（小弟初学，请赐教）

我有一段代码：可以在窗体上实时显示：
<html>
<head>
<title>Time</title><script language="JavaScript">
<!--
function showtime () 
{
var timerID;
var now = new Date();
var hours = now.getHours();
var minutes = now.getMinutes();
var seconds = now.getSeconds();
var timeValue = "" + hours;
timeValue += ((minutes < 10) ? ":0" : ":") + minutes;
timeValue += ((seconds < 10) ? ":0" : ":") + seconds;
document.all["time"].value = timeValue;
timerID = setTimeout("showtime()",1000);
}
-->
</script>
</head><body aLink="#990033" topMargin="0" vLink="#990033" leftmargin="1" background="img/newsun.gif" align="center">
<!--Banner goes here -->
<div align="center">
<table border="0" cellPadding="0" cellSpacing="0" height="60" width="750">
<tr>
     <td width="100" rowspan=2>
     <!-- begin calendar -->           
<table cellpadding="0" cellspacing="4" border="1" bordercolordark="#ffffff" bordercolorlight="#bbbbbb" width="65">           
    <tr>           
<td>           
<center>           
<table width="65" cellpadding="3" cellspacing="0" border="0">           
<tr>           
<td bgcolor="#456589" align="center" valign="top">           
                            <i><font color="#bbbbdd" size="-1">           
                            <input type="text" name="time" id="time" style="font-size:9pt;width:50px; border: 0 solid #000000;background-color:#456589;font-face:verdana,geneva,helvetica;color:#ffffcc;">           
                            <script language="JavaScript">            
                            <!--            
showtime ();                                        
-->            
</script>            
                            </font></i>           
                        </td>           
                    </tr>            
                </table>            
            </center>           
        </td>            
    </tr>            
    <tr>           
<td align="center">           
<table width="65" cellpadding="3" cellspacing="0" border="0">            
<tr>           
<td bgcolor="#fcfcfc">            
<center>            
<font color="#000000" style="font-family: 宋体; font-size: 12;">            
<script language="JavaScript">            
<!--//星期            
var aday=new Array ("日","一","二","三","四","五","六");            
var now=new Date();             
document.write("星期"+aday[now.getDay()]);            
-->            
        </script>            
</font><br>           
<font color="#000000" size="4">            
<script language="JavaScript">            
<!--            
//日            
var now=new Date();            
document.write(now.getDate());            
-->            
</script>            
</font><br>            
<font color="#000000" style="font-family: 宋体; font-size: 12;">            
<script language="JavaScript">            
<!--            
//年月            
var now=new Date();            
document.write(now.getYear()+"年"+(now.getMonth()+1)+"月");            
-->            
</script>            
</font></center>           
</center>            
   </td>            
              </tr>            
           </table>            
        </td>            
    </tr>            
</table>            
<!-- end calendar -->
</td>
    </tr>                
</table>                
</div>               
  
</body>                                  
</html>