hi Brenna,
if you're just trying to do a sum of the credit field within a range, then you can do this:
1) change your formula to
if {gl_detail1.transaction_date} >= date('4/1/2013')
and {gl_detail1.transaction_date} <= date('4/30/2013')
then {gl_detail1.credit};
2) put this formula on the report canvas
3) right click on the formula and choose Insert > Summary and press Okay to accept the defaults
you will not have a summary of the credit field within that range, placed on the Report Footer. you can move this summary to the Report Header if you wish.
