image-upload.php

<?php
// Max size in KB
define('MAX_SIZE', '100');

$errors = 0;

if (isset($_POST['Submit'])) {
	$image = $_FILES['image']['name'];
	if ($image) {
		$fileName = strtolower(pathinfo($image, PATHINFO_FILENAME));
		$ext = strtolower(pathinfo($fileName, PATHINFO_EXTENSION));
		if (($ext != 'jpg') && ($ext != 'jpeg') && ($ext != 'png') && $ext != 'gif') {
			echo '<h1>Unknown extension</h1>';
			$errors = 1;
		} else {
			$imageName = time().'.'.$ext;
			$newName = 'images/'.$imageName;
			$copied = copy($image, $newName);
			if (!$copied) {
				echo '<h1>Copy Unsuccessful</h1>';
				$errors = 1;
			}
		}
	}
}

if (isset($_POST['Submit']) && !$errors) {
	echo '<h1>File Uploaded Sucessfully</h1>';
}