I hope that we will work together as a community to share and improve our calculations. When you upload a file you give it a version number and it can be up-issued by the author at any time. I posted a calculation a couple of days ago a user called yukimura left a comment on the calculation and I updated it to version 2 this morning. see http://www.excelcalcs.com/component/option,com_remository/func,fileinfo/id,242/

The Repository is not the best place to develop calculations it is better done through the Forum - you can attach excel files and images to posts and you'll have a better dialogue with other users here. The finished calculation can be posted to the forum.

The Repository rating system allows users to highlight problems with calculations if they are spotted. User ratings and comments are essential for guiding other members to good content on the site.