Try this
<?php
$destination='aircraft/'.$reg."1.jpg";
$temp_file = $_FILES['image']['tmp_name'];
move_uploaded_file($temp_file,$destination);
imgresize($destination);
$destination2='aircraft/'.$reg."2.jpg";
$temp_file2 = $_FILES['image2']['tmp_name'];
move_uploaded_file($temp_file2,$destination2);
imgresize($destination);
$destination3='aircraft/'.$reg."3.jpg";
$temp_file3 = $_FILES['image3']['tmp_name'];
move_uploaded_file($temp_file3,$destination3);
imgresize($destination);
function imgresize($filename) {
$source = imagecreatefromjpeg($filename);;
$fullpath = $filename;
list($width, $height) = getimagesize($filename);
$thumb = imagecreatetruecolor($newwidth, $newheight);
imagecopyresampled($thumb,$source,0,0,0,0,200, 133,$width,$height);
imagejpeg($thumb, 'images/thumbs/'.basename($filename), 100);
}
?>