disable save button when payment type is not Refund

Summary:

Content (please ensure you mask any confidential information):

tried this code, but did not work

#{!(pageFlowScope.createPaymentBean.hasInvoicesInTheTable && pageFlowScope.createPaymentBean.paymentIsValid && pageFlowScope.createPaymentBean.isCrossCurrRateDefined) && bindings.PaymentTypeFlag.inputValue != 'R'}

Version (include the version you are using, if applicable):

Code Snippet (add any code snippets that support your topic, if applicable):