php upload script

<?php
$target_dir = "tictacttoe/inventory/";
$target_file = $target_dir . basename($_FILES["fileName"]["name"]);
$uploadOk = 1;
//$imageFileType = strtolower(pathinfo($target_file,PATHINFO_EXTENSION));
// Check if image file is a actual image or fake image
//if(isset($_POST["submit"])) {
    //$check = getimagesize($_FILES["fileName"]["tmp_name"]);
    if ($_FILES["fileName"]["size"] > 500000) {
    print "Sorry, your file is too large.";
    $uploadOk = 0;
}
if (file_exists($target_file)) {
    echo "Sorry, file already exists.";
    $uploadOk = 0;
}
if ($uploadOk == 0) {
 echo "Sorry, your file was not uploaded.";
// if everything is ok, try to upload file
} else {

    if (move_uploaded_file($_FILES["fileName"]["name"], $target_file)) {
        echo "The file ". basename( $_FILES["fileName"]["name"]). " has been uploaded.";
    } else {
        echo "Sorry, there was an error uploading your file.";
    }
}
//}
?>