I wonder if anyone can help me.

I have a job process form where by the user records a job undertaken, which calculates agains a job form. So there is a list of jobs complete in a report. 

I want to a separate form where the user can select a month of the year, and it will calculate the earnings over that period.

I have attached a screenshot below of the "Job Proccess Form" which i would like to build this new form from.

Thanks for your help in advance.

Danny