Reverse a String??

<?php
        function createImage($str) {
            header("Content-type: image/png");
            $handle = ImageCreate(180, 50);
            ImageColorAllocate($handle, 255, 0, 0);
            $txt_color = ImageColorAllocate($handle, 255,255, 255);
            ImageString($handle, 5, 15, 18, $str, $txt_color);
            imageflip($handle, IMG_FLIP_HORIZONTAL);
            ImagePng($handle);
        }
        createImage('This is a string');