Display method

display Amount JournalAmount()
{
    Paymentrequest Paymentrequest;
    Paymentrequestline Paymentrequestline;

    select Paymentrequest where Paymentrequest.PaymentjournalID == this.PaymentjournalID;
    select sum(Amount) from Paymentrequestline where Paymentrequestline.JournalNum == Paymentrequest.JournalNum;
    return Paymentrequestline.Amount;