GD and Converting a Transparent PNG-8 to a Transparent GIF

Hi I am having problems getting GD to convert a transparent PNG-8 to a transparent GIF The below WILL produce a GIF...but leaves a white background # Convert the PreExisting PNG Image to a GIF $img = imagecreatefrompng($pngPath); # Set the GIF to be transparent: Does not seem to work $trans_color = imagecolortransparent($img ); $trans_index = imagecolorallocate($img, $trans_color['red'], $trans_color['green'], $trans_color['blue'] ); imagecolortransparent($img, $trans_index ); # Save the Image as a GIF in the directory imagegif($img, $gifAbsolutePath); Is there another way that works? Many thanks in advance G