WEBI Report Use of Variable in Drill Down

Hi,

i am new to BI Webi report just doing some practice exercise from E fashion Universe. Need your help in creating a WEBI report which should show Sales Revenue broken down to half-year level.

For example:

We have Year, when we drill Year 2004, it should not show Quarter infect i want to see 1st Half Year as Q1;Q2 and 2nd Half year as Q3;Q4 for that year.

For this i have created a Variable "Half Year"

=If([Quarter]InList("Q1";"Q2");"1st Half Year"; "2nd Half Year")

Is there anyway i can use this variable so when i drill Year it should Sales Revenue Broken as Half Year

Thanks