File Upload

<?php
$target_dir = "uploads/";
$target_file = $target_dir . basename($_FILES["fileToUpload"]["name"]);
$new_target_file = $target_dir . "banner." . pathinfo($target_file, PATHINFO_EXTENSION);
$uploadOk = 1;
$imageFileType = pathinfo($target_file, PATHINFO_EXTENSION);

//Check if file exists
if (file_exists($target_file)) {
    echo "Sorry, file already exists.<br>";
    $uploadOk = 0;
}

//Check file size
if ($_FILES["fileToUpload"]["size"] > 5000000) {
    echo "Sorry, your file is too large. (5mb)<br>";
    $uploadOk = 0;
}

//Allow certain file formats
if ($imageFileType != "jpg" && $imageFileType != "png" && $imageFileType != "jpeg" && $imageFileType != "gif" && $imageFileType != "JPG") {
    echo "Sorry, only JPG, JPEG, PNG & GIF files are allowed.<br>";
    $uploadOk = 0;
}

if (isset($_POST["submit"])) {
    $check = getimagesize($_FILES["fileToUpload"]["tmp_name"]);
    if ($check !== false) {
        echo "File is an image - " . $check["mime"] . ".<br>";
        $uploadOk = 1;
    } else {
        echo "File is not an image.<br>";
        $uploadOk = 0;
    }
}

if ($uploadOk == 0) {
    echo "Sorry, your file was not uploaded.";
} else {
    if (move_uploaded_file($_FILES["fileToUpload"]["tmp_name"], $new_target_file)) {
        echo "The file " . basename($_FILES["fileToUpload"]["name"]) . " has been uploaded.<br>";
    } else {
        echo "Sorry, there was an error uploading your file.<br>";
    }
}
?>