PHP example four file upload

<form method = "post" action = "upload.php" enctype="multipart/form-data">;
 <input type = "hidden" name = "MAX_FILE_SIZE" value ="10000000">
   需求上传：<input type = "file" name = "myfile" >;
<p> <input type = "submit" name = "submit" value = "确定上传"></p>;
</form>;

<?php
 $allowtype = array("gif","png","jpg","doc","txt");     //上传图片的格式
 $size = 10000000;                         //允许最大上传是10M
 $path = "./uploads";                     //上传后的路径
 
//判断是否成功的上传了服务器，0表示上传成功
 if($_FILES[&#39;myfile&#39;][&#39;error&#39;] > 0)
 {
   echo '上传错误：';
   switch($_FILES['myfile']['error']){
     case 1: die('上传大小超过了限定值：upload_max_filesize');
     case 2: die('上传大小超过了表单中的约定值：MAX_FILE_SIZE');
	 case 3: die('文件只有部分上传！');
	 case 4: die('没有上传任何文件！');
	 default：die('未知错误');
   }
 }
  $linshi =explode(".",$_FILES['myfile']['name']);
//判断上传的文件是否符合允许的格式
 $hz = array_pop($linshi);//数组获取文件的名称包括扩展名
 //方法是判断后缀
 if(!in_array($hz,$allowtype))
  {
    die("这个后缀<b>{$hz}</b>不是允许的文件类型");
  }

//判断大小是否符合
  if($_FILES['myfile']['size']>$size)
  {
   die('超过了允许的<b>{$size}</b>字节大小');
    
  }
  //$filename = date("YmdHis").rand(100,999).".".$hz;

 if(is_uploaded_file($_FILES['myfile']['tmp_name']))
 {
   if(!move_uploaded_file($_FILES['myfile']['tmp_name'],$path.'/'.$_FILES['myfile']['name']))
	 {
           die('不能将文件移至指定目录！');   
     }
	 

  
   
 }else
	 {
	       die('不是指定文件！');
	 }

	 
   echo"<center>";
	 echo "您好!</br>";
echo "您的文件:{$_FILES['myfile']['name']}已上传成功！大小为{$_FILES['myfile']['size']}字节！";
echo"我们会及时处理并联系您,请您耐心等待。";
echo "</br>";
echo "<a href = &#39;index.php&#39;>返回首页</a>";

echo "</center>";



?>