Fatal error: Cannot use string offset as an array

$userinfo=M('userinfo');
$price=$userinfo->query("SELECT feilv,free_count FROM msgfl,userinfo WHERE msgfl.t_id=userinfo.t_id AND uiid=$uiid AND msgfl.type=2");

$price=$price[0]["FEILV"];
$free_count=$price[0]["FREE_COUNT"];
到上面那行报错
Fatal error: Cannot use string offset as an array

$price 明明返回的是个数组，为什么会报错呢

知道怎么回事了 变量的问题。。