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Cita: How can I use EasyGallery on my Website?
You can include EasyGallery to your website by adding <?php include("yourpath/EasyGallery.php"); ?> into your code. Copy the slimbox folder to the location of your website. Remember to change the .html file ending into .php and the $root_dir variable in EasyGallery.php
cambioa el $root_dir en el archivo EasyGallery.php me imagino que esa es la ruta de la carpeta de las imagenes.