49647 Oscommerce Adjustments

My website([login to view URL])works fine but 2 things need to be fixed: 1) The custom made module that calculates the shipping costs. It works fine but it just needs to be updated. For 12 products shipping should be 15 euro and any extra item should cost 0.50 extra per item to ship. 2) An error is bugging my webshop: Warning: order_total(includes/languages/dutch/modules/order_total/[login to view URL]): failed to open stream: No such file or directory in /home/kroeshaa/public_html/webshop/includes/classes/[login to view URL] on line 26 If you are experienced it's a 3 to 4 hour job at the max.