Convert a few lines of code to a Joomla module with explanation

We are looking for someone to change a few lines of code in to a Joomla module and explain the process. Requirements: - Data in a form - Display error messages - Some calculations on fields that return a result in the same position - Every line of code must be very clearly documented or has to be explained - We prefer to have contact true Skype Check the attachments for the files that need to become a Joomla module. This is a very simple test project. We are looking for someone to work with for a large project.