用getdate函数取得系统的日期与时间--------------------------------------------------------------------------------
getdate函数返回一个哈希数组,可以通过 "seconds","minutes","hours",    
"mday","wday","mon","year","yday","weekday","month"下标进行访问。     
以下是一个访问的实例:    
<?   
   $DateEnum=array("seconds","minutes","hours","mday","wday","mon","year","yday","weekday","month");
   $CurrentDate=getdate();   
   for ($i=0;$i<10;$i++)      
   {     
       echo $DateEnum[$i]."=".$CurrentDate[$DateEnum[$i]]."<br>";      
   }    
?>    如时间若为:1999-10-2  18:17:16
则对应结果如下:
   seconds=16
   minutes=17
   hours=18
   mday=12
   wday=2
   mon=10
   year=1999
   yday=284
   weekday=Tuesday
   month=October