Change the value of working days with user input

[Anonymous]

I have a pivot table in which I'm calculating the amount of working days as Cycle1_WD + Cycle2_WD + Cycle3_WD,per year..
How can I modify the expression so that, if a Cycle is selected, the "working days" value equals the value of the Cycle<cycle_number>_WD, and if none is selected, the "working days" expression is calculating Cycle1_WD + Cycle2_WD + Cycle3_WD?

Cycle1_WD,Cycle2_WD,Cycle3_WD are variables calculated in the loading script.

[darrell_tobin]

sum(

     If (

     (count(Distinct Cycle) = 1 and Cycle = 'Working days'),

     Cycle<cycle_number>_WD,

     Cycle1_WD + Cycle2_WD + Cycle3_WD

     )//if close

     )//sum close

This may work.

logic is more

[Anonymous]

Cycle is a field in my table that can take one of the three values: Cycle1,Cycle2,Cycle3. The value of the Cycle field filters the activities by its value.
I need an expression like:

if(<Cycle is selected with value x>, Cyclex_WD, Cycle1_WD + Cycle2_WD + Cycle3_WD)