用于创建文件夹的脚本不再起作用

This code was working some days ago... now I'm not sure what is going wrong.. Could someone shed a light or propose a better idea ?

<?php
$album = $_POST['name'];
function create_album($album){
    $albumPath = "albums/".$album;
    if (is_dir($albumPath)){
        echo('Album already exists.');
    }
    else{
        mkdir($albumPath);
        echo ("The album $album was created successfully");
    }
}
?>

You are missing a call to the function.

<?php
$album = $_POST['name'];
function create_album($album){
    $albumPath = "albums/".$album;
    if (is_dir($albumPath)){
        echo('Album already exists.');
    }
    else{
        mkdir($albumPath);
        echo ("The album $album was created successfully");
    }
}

create_album($album);
?>