php写下mysql中文乱码啊已经是utf8了

$conn = mysql_connect("localhost","test","test");
if (!$conn)
  {
  die('Could not connect: ' . mysql_error());
  }
//mysql_query("set test 'utf8'");
mysql_set_charset("utf8" , $conn); 
//选择数据库
mysql_select_db("test", $conn);

//往表里插数据
mysql_query("INSERT INTO test (id, myusername) 
VALUES (2,'中文2')");

//mysql_query("INSERT INTO user (id, myusername) 
//VALUES (". intval($str_id) . "," . $str_name . ")");

//关闭数据库连接
mysql_close($conn);