图片上传类,上传多个不同图片后,好几张显示相同的图片:

uppoo.php 文件内容:
<?php
class upphoto{
public $previewsize=0.5  ;   //预览图片比例
public $preview=1;   //是否生成预览，是为1，否为0
    public $datetime;   //随机数
    public $ph_name;   //上传图片文件名
    public $ph_tmp_name;    //图片临时文件名
    public $ph_path="./userimg/";    //上传文件存放路径
public $ph_type;   //图片类型
    public $ph_size;   //图片大小
    public $imgsize;   //上传图片尺寸，用于判断显示比例
    public $al_ph_type=array('image/jpg','image/jpeg','image/png','image/pjpeg','image/gif','image/bmp','image/x-png');    //允许上传图片类型
    public $al_ph_size=1000000;   //允许上传文件大小
  function __construct(){
    $this->set_datatime();
  }
  function set_datatime(){
   $this->datetime=date("YmdHis");
  }
   //获取文件类型
  function get_ph_type($phtype){
     $this->ph_type=$phtype;
  }
  //获取文件大小
  function get_ph_size($phsize){
     $this->ph_size=$phsize."<br>";
  }
  //获取上传临时文件名
  function get_ph_tmpname($tmp_name){
    $this->ph_tmp_name=$tmp_name;
    $this->imgsize=getimagesize($tmp_name);
  }
  //获取原文件名
  function get_ph_name($phname){
    $this->ph_name=$this->ph_path.$this->datetime.strrchr($phname,"."); //strrchr获取文件的点最后一次出现的位置
//$this->ph_name=$this->datetime.strrchr($phname,"."); //strrchr获取文件的点最后一次出现的位置
return $this->ph_name;
  }
// 判断上传文件存放目录
  function check_path(){
    if(!file_exists($this->ph_path)){
     mkdir($this->ph_path);
    }
  }
  //判断上传文件是否超过允许大小
  function check_size(){
    if($this->ph_size>$this->al_ph_size){
     $this->showerror("上传图片超过2000KB");
    }
  }
  //判断文件类型
  function check_type(){
   if(!in_array($this->ph_type,$this->al_ph_type)){
         $this->showerror("上传图片类型错误");
   }
  }
  //上传图片
   function up_photo(){
   if(!move_uploaded_file($this->ph_tmp_name,$this->ph_name)){
    $this->showerror("上传文件出错");
   }
  }
  //图片预览
   function showphoto(){
      if($this->preview==1){
      /*
  if($this->imgsize[0]>2000){
        $this->imgsize[0]=$this->imgsize[0]*$this->previewsize;
             $this->imgsize[1]=$this->imgsize[1]*$this->previewsize;
      }
  */
    $this->imgsize[0]=$this->imgsize[0]*$this->previewsize;
        $this->imgsize[1]=$this->imgsize[1]*$this->previewsize;
         echo("<img src=\"{$this->ph_name}\" width=\"{$this->imgsize['0']}\" height=\"{$this->imgsize['1']}\">");
     }
   }
  //错误提示
  function showerror($errorstr){
    echo "<script language=java script>alert('$errorstr');location='java script:history.go(-1);';</script>";
   exit();
  }
  function save(){
   $this->check_path();
   $this->check_size();
   $this->check_type();
   $this->up_photo();
   $this->showphoto();
   
  }
}
?>
 upphoto.php 内容如下:
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>无标题文档</title>
</head><body>
<?php
header("Content-Type:text/html; charset=utf-8"); 
//类的实例化：
include("lib/uppoo.php");//类的文件名是upoop.php
$up=new upphoto;
$up2=new upphoto;
$up3=new upphoto;
$up4=new upphoto;
$up5=new upphoto;
$up6=new upphoto;$submit=$_POST['submit'];
if($submit=="上传"){
$up->get_ph_tmpname($_FILES['photo']['tmp_name']);
$up->get_ph_type($_FILES['photo']['type']);
$up->get_ph_size($_FILES['photo']['size']);
$up->get_ph_name($_FILES['photo']['name']);
$up->save();$up2->get_ph_tmpname($_FILES['photo2']['tmp_name']);
$up2->get_ph_type($_FILES['photo2']['type']);
$up2->get_ph_size($_FILES['photo2']['size']);
$up2->get_ph_name($_FILES['photo2']['name']);
$up2->save();
$up3->get_ph_tmpname($_FILES['photo3']['tmp_name']);
$up3->get_ph_type($_FILES['photo3']['type']);
$up3->get_ph_size($_FILES['photo3']['size']);
$up3->get_ph_name($_FILES['photo3']['name']);
$up3->save();
$up4->get_ph_tmpname($_FILES['photo4']['tmp_name']);
$up4->get_ph_type($_FILES['photo4']['type']);
$up4->get_ph_size($_FILES['photo4']['size']);
$up4->get_ph_name($_FILES['photo4']['name']);
$up4->save();
$up5->get_ph_tmpname($_FILES['photo5']['tmp_name']);
$up5->get_ph_type($_FILES['photo5']['type']);
$up5->get_ph_size($_FILES['photo5']['size']);
$up5->get_ph_name($_FILES['photo5']['name']);
$up5->save();
$up6->get_ph_tmpname($_FILES['photo6']['tmp_name']);
$up6->get_ph_type($_FILES['photo6']['type']);
$up6->get_ph_size($_FILES['photo6']['size']);
$up6->get_ph_name($_FILES['photo6']['name']);
$up6->save();}
?>
test_upimg.php代码如下:<form action="upphoto.php?action=act" method="post" enctype="multipart/form-data">
图片来源：<input type="file" name="photo"><br />
<input type="file" name="photo2"><br />
<input type="file" name="photo3"><br />
<input type="file" name="photo4"><br />
<input type="file" name="photo5"><br />
<input type="file" name="photo6"><br />
<input type="submit" name="submit" value="上传"> 
</form></body>
</html>
问题:
上传多个不同图片时,上传预览结果,有好几张相同图片.请问这个怎么解决 ?
谢谢