I have a field in a detail line that I want to conditionally sum.  To this this I am trying to use the "Running Total" function witha formula.  My understanding was that if the formuala evulated to true the number would be summed.  However Crystal 8 is not liking my formula.  Here is what I have.

 

if {Po_noteExtensionBase.Po_EffectiveDate} in {?BeginingDataRange} to {?EndingDateRange}

 

Crystal says it needs a "then" to complete the if statement, which makes sense but what do I put?  If the condition is true I want it to accumulate a total for the field it is summing.

 

Thanks for the help.