Crystal Reports Need Formula to Display Quarter

Message

     Hi everybody....need a little formula help here. The formula below works for me to pull my Account Balances for Year To Date:

if {GLPerBal.FiscalYear} = year({?End Date Year}) then
  if {GLPerBal.FiscalPeriod} <= month({?End Date Year}) then
{GLPerBal.CreditAmt} + {GLPerBal.DebitAmt}

I am scratching my head trying to figure out how to change it so it just displays quarterly info. For example, if it is the first qtr, I just want data for Jan Feb Mar, if it is second qtr I just want data for Apr May Jun.

Is there anybody good with formulas that can crack this?

Thanks!