Reporting: If statement and Sum statement

I have an instructors schedule that shows each time a course is taught for example:

Course   Credits   Day

AAA123       3       Mon.

                             Wed.

The Credit only shows the first time (Print When Condition: calc.counter IS 1). I need to total the credits for each course when I use the Sum(credits) function it totals for each line (the above ezample would show a total of 6), I only want to sum if calc.counter EQ 1