问PHP，在目录中创建文件

EN

localhost
--/tdir/
---/(random number directory) < this is were i want to save to the text file

    <?php
            $dir = rand(1, 1999999);
            if (!file_exists($dir)) {
            mkdir($dir, 0777, true);
        }
            if ($dir == true) {
                echo "Created directory! :D";
            } else {
                echo "Failed to create directory! ~ :(";
            }

        chmod("/tdir/$dir/", 0777);
        echo "</br><a href='/tdir/'>Go Back</a>";
        echo "</br><a href='/tdir/$dir'>Go to page!</a></br>";
        $my_file = '../'.$dir.'/file.txt';
        $handle = fopen($my_file, 'w') or die('Cannot open file:  '.$my_file);
        $data = 'This is the data';
        fwrite($handle, $data);
    ?>

Created directory! :D
Go Back
Go to page!
Cannot open file: ../1320710 *random number directory* /file.txt