If Or Statement not working PHP

I am making a site where you can upload files. I just want people to upload Word, Powerpoint, Excel, PDF and JPG files. Therefore, I made this if-statement:

$target_dir = "files/";
$target_file = $target_dir . basename($_FILES["fileToUpload"]["name"]);
$filename = basename($_FILES["fileToUpload"]["name"]);
$uploadOk = 1;
$fileType = pathinfo($target_file,PATHINFO_EXTENSION);
// Check if file selected
if (!isset($_FILES['fileToUpload']) || $_FILES['fileToUpload']['error'] == UPLOAD_ERR_NO_FILE) {
    $msg = "No file selected. Try again.";
    $uploadOk = 0;

} elseif (file_exists($target_file)) { // does file already exist?
    $msg = "File already exists.";
    $uploadOk = 0;

} elseif ($_FILES["fileToUpload"]["size"] > 10485760) { // filesize
    $msg = "File too huge.";
    $uploadOk = 0;

// THE PROBLEM IS IN THE FOLLOWING STATEMENT

} elseif ($fileType != "jpg" || $fileType != "doc" || $fileType != "docx" || $fileType != "ppt" || $fileType != "pptx" || $fileType != "xls" || $fileType != "xlsx" || $fileType != "pdf") {
    $msg = "Filetype not allowed";
    $uploadOk = 0;
}

if ($uploadOk != 0) {
    if (move_uploaded_file($_FILES["fileToUpload"]["tmp_name"], $target_file)) {
        $msg = "File uploaded.";
    } else {
        $msg = "File not uploaded.";
    }

However, when I upload a JPG,PDF,PHP or whatever, it always gives the error : Filetype not allowed. What am I doing wrong?