关于PHP图片上传问题


上传图片总是提示 上传的文件不存在。<form action="upload.php" method="post" enctype="multipart/form-data" name="pic1" id="pic1"  >
  <p>
    <label>
      <input type="file" name="file" id="file" />
    </label>
  </p>
  <p>
    <label>
      <input type="submit" name="button" id="button" value="提交" />
    </label>
  </p>
</form>------------------------------------------------------
$file=new upfile("file");
$file->is_upload_file();
$file->check_file_name();
$file->is_big();
$file->check_type();
$f_name=$file->upload_file();
$f_name=str_replace('../../','',$f_name);
$file->create_simg(100,100);