php上传mp4的问题

[hfsross]

为什么上传torrent的时候没问题，上传mp4的时候就提示文件类型不对
而且echo($_FILES['userfile']['name']);输出为空

		case "mp4":
			$uploaddir = '../mp4/';
			$uploaddir2 = 'mp4/';
			echo($_FILES['userfile']['name']);
			$timename=time();
			$uploadfile = $uploaddir.$timename.$_FILES['userfile']['name'];
			$uploadfile2=$uploaddir2.$timename.$_FILES['userfile']['name'];
			if ($_FILES['userfile']['size']>52428800)
			{
				print "您上传的文件太大";
				exit(0);
			}
			//print($_FILES['userfile']['type']);
			switch ($_FILES['userfile']['type']) {
				case "application/octet-stream":
				break;
				default:
				print "您上传的文件类型不对<a href='up.php?class=mp4'>重新上传</a>";
				exit(0);
				break;
			}
			$filetype=explode(".",$uploadfile);
			if ($filetype[count($filetype)-1]!="torrent"&&$filetype[count($filetype)-1]!="mp4"){
				print "您上传的文件类型不对<a href='up.php?class=mp4'>重新上传</a>";
				exit(0);
			
			if (move_uploaded_file($_FILES['userfile']['tmp_name'],$uploadfile))
			{}
				print "文件上传成功";
				print "<script language='javascript'>parent.document.getElementById('mp4').value+='http://www.hzhu.com/".$uploadfile2."';</script>" ;
				print "<script language='javascript'>parent.document.getElementById('mp4').value+=\"\\r\\n\";</script>";
				print "<script language='javascript'>document.getElementById('upload').style.display='none';</script>";
				print "<a href='up.php?class=mp4'>继续上传</a>";
			}
			else
			{
			print "上传文件失败!  文件的错误信息:\n";
			switch ($_FILES['userfile']['error'])
			{
				case 1:
					print "您所上传的文件太大\n";
					print "<a href='up.php?class=mp4'>重新上传</a>";
				break;
				case 2:
					print "您所上传的文件太大\n";
					print "<a href='up.php?class=mp4'>重新上传</a>";
				break;
				case 3:
					print "只有部分文件上传\n";
					print "<a href='up.php?class=mp4'>重新上传</a>";
				break;
				case 4:
					print "没有上传文件\n";
					print "<a href='up.php?class=mp4'>重新上传</a>";
				break;
				default:
				print "其它不明错误";
				print "<a href='up.php?class=mp4'>重新上传</a>";
			}
			}
		break;

[swyuyang]

应该是你自己的吧。其它不明错误";