<code lang="PHP">
function createthumb($IMAGE_SOURCE,$THUMB_X,$THUMB_Y,$OUTPUT_FILE,$ASPECT="true",$format="jpg"){
  $BACKUP_FILE = $OUTPUT_FILE . "_backup.$format";
  copy($IMAGE_SOURCE,$BACKUP_FILE);
  $IMAGE_PROPERTIES = GetImageSize($BACKUP_FILE);
  if (!$IMAGE_PROPERTIES[2] == 2) {
   return(0);
  } else {
  	if($format=="jpg")
   	$SRC_IMAGE = ImageCreateFromJPEG($BACKUP_FILE);
   else 
   	$SRC_IMAGE = ImageCreateFromGIF($BACKUP_FILE);
   $SRC_X = ImageSX($SRC_IMAGE);
   $SRC_Y = ImageSY($SRC_IMAGE);
   if($ASPECT=="true")
	{
		   $SCALEX = $THUMB_X/($SRC_X);
		   $SCALEY = $THUMB_Y/($SRC_Y);
		   if (($THUMB_Y == 0) && ($THUMB_X == 0)) {
			 return(0);
		   } elseif ($THUMB_Y == 0) {
			 $THUMB_Y = $SRC_Y*$SCALEX;
			 $RATIO=MAX($SCALEY,$SCALEX);
		   } elseif ($THUMB_X == 0) {
			 $THUMB_X = $SRC_X*$SCALEY;
			 $RATIO=MAX($SCALEY,$SCALEX);
		   }
		   if($SCALEY>0 && $SCALEY<1 && $SCALEX>0 && $SCALEX<1)
				$RATIO=MIN($SCALEY,$SCALEX);
		   elseif($SCALEX>1 || $SCALEY>1)
				$RATIO=MAX($SCALEY,$SCALEX);
			
			$THUMB_X=$SRC_X*$RATIO;   		
			$THUMB_Y=$SRC_Y*$RATIO;  
	}
	else
	{ 
	$RATIO=1; 
	}
   $THUMB_X = (int)($THUMB_X);
   $THUMB_Y = (int)($THUMB_Y);
   $DEST_IMAGE = imagecreatetruecolor($THUMB_X, $THUMB_Y);
   unlink($BACKUP_FILE);
   if (!imagecopyresampled($DEST_IMAGE, $SRC_IMAGE, 0, 0, 0, 0, $THUMB_X, $THUMB_Y, $SRC_X, $SRC_Y)) {
     imagedestroy($SRC_IMAGE);
     imagedestroy($DEST_IMAGE);
     return(0);
   } else {
     imagedestroy($SRC_IMAGE);
     if (ImageJPEG($DEST_IMAGE,$OUTPUT_FILE)) {
       imagedestroy($DEST_IMAGE);
       return(1);
     }
     imagedestroy($DEST_IMAGE);
   }
   return(0);
  }

}
</code>