PHP我做错了什么？

I'm trying to use PHP to detect certain languages. However, no matter what, it only echos "FR" I don't know why.

<?php
    $lang = "en";
    if ($lang == "fr" OR "nl") {
        echo "FR";
    } else {
        echo "Nope";
    }
?>

EDIT: How about this?

<?php
    $lang = "FR";
    $numarray = array(1, 2); //change the values accordingly.
    if ($lang === "fr" OR $lang === "nl") {
        echo "FR";
    } elseif(array_rand($numarray) == 1) {
        echo "Outcome1";
    } else {
        echo "Outcome2";
    }
?>

EDIT: I found the problem. Strings are case sensitive.

$lang = "en";
if ($lang === "fr" OR $lang === "nl") {
    echo "FR";
} else {
    echo "Nope";
}

You almost had it. OR needs two statements so just think of each side of the or needing brackets if (($land === "fr") OR ($land === "nl"))

see u r using OR incorrectly try this it works

<?php
    $lang = "en";
    if ($lang == "fr" or $lang== "nl") {
        echo "FR";
    } else {
        echo "Nope";
    }
?>

== comparison operator will give unexpected results specially when using strings..

try using the following script

<?php
    $lang = "en";
    if ($lang === "fr" OR $lang === "nl") {
        echo "FR";
    } else {
        echo "Nope";
    }
?>