ช่วยดูหน่อยครับ ว่าผิดตรงไหน เรื่อง Upload File ช่วยดูหน่อยครับ ว่าผิดตรงไหน พอ upload แล้ว

if($_FILES["fileupload"]["name"])
{


 
      $fileupload = $_FILES['fileupload']['tmp_name'];
      $fileupload_name = $_FILES['fileupload']['name'];
      $fileupload_size = $_FILES['fileupload']['size'];
      $fileupload_type = $_FILES['fileupload']['type'];
 
      $ext = strtolower(end(explode('.',$fileupload_name)));
		
	  if($ext=='doc' || $ext=='pdf' || $ext=='xls' || $ext=='ppt' || $ext=='zip' || $ext=='rar')
	  {
	      
	     $filename = md5(rand() * time()).".".$ext;
	     @copy($fileupload,"documents/$filename");
	     @unlink($fileupload);
	   			
	  }else{
	 
	 
	     echo "<script language='javascript'>alert('Can upload file. Please try again.');</script>";
         echo"<script>history.back();</script>"; 
         exit();
	 	 
	}


}