функция imagerotate не работает

function resample($jpgFile, $width, $newcopy, $orientation) {
// Get new dimensions
list($width_orig, $height_orig) = getimagesize($jpgFile);
$height = (int) (($width / $width_orig) * $height_orig);
// Resample
$image_p = imagecreatetruecolor($width, $height);
$image   = imagecreatefromjpeg($jpgFile);
imagecopyresampled($image_p, $image, 0, 0, 0, 0, $width, $height, $width_orig, $height_orig);
// Fix Orientation
switch($orientation) {
case 3:
$image_p = imagerotate($image_p, 180, 0);
break;
case 6:
$image_p = imagerotate($image_p, -90, 0);
break;
case 8:
$image_p = imagerotate($image_p, 90, 0);
break;
}
// Output
imagejpeg($image_p, $newcopy, 90);
echo "Rotated Image Copied to Destination.<BR>";}