PHP Easy Upload

<?php
if($_GET['do'] == "up") {
        @move_uploaded_file($_FILES['file']["tmp_name"], "files/" . $_FILES['file']['name']);
}
?>
<form action="?do=up" method="post" enctype="multipart/form-data" name="form1" id="form1"><br />
<label>
<input type="file" name="file" />
</label>
<br />
<label>
<input type="submit" name="Submit" value="upload" />
</label>
</form>