Variable in script logic

Question

Follow is the script code from previous post
*XDIM_MEMBERSET ACCOUNT = ACC1
*FOR %My_Var% = %ENTITY_DIM%
*WHEN ENTITY
*IS *
*REC(EXPRESSION = (GET (ENTITY = %My_Var%.PROP1)), ENTITY = %My_Var%)
*ENDWHEN
*NEXT
I understand that  both %My_Var% and %ENTITY_DIM% are variables, my question is how %My_Var% and %ENTITY_DIM% get the value during the process of the code, do we neeed to define the variable some where else before we use them? I remeber in FOX, we need to define the variable before we can use it.
also is there a difference if I use $My_Var$ to replace %My_Var%?

Answer 1

nilanjan,
Thanks for the explanation,I have another question regarding to the variables.
I need to get the YTD salary. in BPS the pseudocode code is as following:
data YTD_salary type amount
loop at each_month,
   YTD-Salary =  YTD-Salary  + current_month.
   if the  YTD-Salary  > FICA CAP.
   exit.
Endloop
How can we archive the same in BPC script logic with a variable to capture the YTD-Salary and pass it to next month?