<?php
$target_dir = "uploads/";
$target_file = $target_dir . basename($_FILES["fileToUpload"]["name"]);
$uploadOk = 1;
$imageFileType = strtolower(pathinfo($target_file,PATHINFO_EXTENSION));
if(isset($_POST["submit"])) {
    $check = true;
    if($check !== false) {
        echo "Correct file - " . $check["mime"] . ".";
        $uploadOk = 1;
    } else {
        echo "Incorrect file.";
        $uploadOk = 0;
    }
}

if ($_FILES["fileToUpload"]["size"] > 500000) {
    echo "Sorry, your file is too large.";
    $uploadOk = 0;
}

if($imageFileType != "nn" ) {
    echo "Sorry, only .nn files are allowed.";
    $uploadOk = 0;
}
if ($uploadOk == 0) {
    echo "Sorry, your file was not uploaded.";
// if everything is ok, try to upload file
} else {
    if (move_uploaded_file($_FILES["fileToUpload"]["tmp_name"], $target_file)) {
        echo "The file ". basename( $_FILES["fileToUpload"]["name"]). " has been uploaded.";
        header("Refresh:0");
    } else {
        echo "Sorry, there was an error uploading your file.";
    }
}
?>