How to build a counter to add virtual costs?

Question

Dear all,
I am just starting to useAdobe Captivate - mainly for elearning labs for medicine students. I have to following problem to resolve:
To a given medical record, students should be able to choose diagnostics - see e.g. x-rays on a seperate page. To make them thinking about what diagnostic is the first choice and what are the costs, I need a kind of counter that adds the costs of diagnostics to a bill.
I wanted to resolve this using a variable, and whenever a diagnostic page (e.g. five different available) is choosen for the first time, the amount that this diagnostic means costs should be added to the variable (once).
This total amount should be shown for the case to demonstrate total costs of the diagnostics choosen.
Can anyone give me a hint how to do that?
Thank you.

Answer 1

Hello,
I suppose those 'diagnostics' are on different slides? If not, please give some more details. If there are on different slides, and you provide navigation with buttons or other interactive objects on the main slide (you didn't tell which version you use?), here is a very simple scenario:
Create 6 user variables: v_counter (will store the sum), v_diag1, v_diag2, v_diag3, v_diag4, v_diag5, all with a default value=0
Create the image of a counter and put a text container in it, showing the user variable v_counter; put this image on the first slide where you want to show it, and time it for the rest of the project, preferably with the option 'Always on top'. You can hide it  from the slide where you do not want to see it any more if necessary.
On entering each diagnostic slide, trigger a standard advanced advanced action EnterDiag1, EnterDiag2.... EnterDiag5 with these statements:  
    Assign v_dagn with X    n=number of that diagnostic page (you have to create a different action for each), X is the score for that page)
    Expression v_counter = v_diag1 + v_diag2
    Expression v_counter = v_counter + v_diag3
    Expression v_counter = v_counter + v_diag4
    Expression v_counter = v_counter + v_diag5
You need that much expressions because Captivate allows only one operator and has no functions.
Use duplicate for the advanced actions, only the first statement (Assign) has to be changed for each action.
Lilybiri