How to give if condition for propercase and uppercase in sap crystal report

I am getting two values one is printing Cash and other is printing CASH in sap crystal report. Now, I want that wherever Cash is showing at that time value should be false while if CASH is printing then the value should show true. So, for that I added the formula but didnt work,

here is my formula,

if(ProperCase({TmpSalesBillInstallmentReport.PaymentType}) = true)
then {TmpSalesBillInstallmentReport.PaymentType}= '0'
else if(UpperCase({TmpSalesBillInstallmentReport.PaymentType}) = true)
{TmpSalesBillInstallmentReport.PaymentType} = '1'

This formula is not working, even getting error i.e. A Boolean Is Required Here(indicating on the first line)

I surfing in net but didnt get related question also.