PL/SQL Exceptions

FUNCTION generate_amortization_sched_fn (i_transaction_id IN XXHLS.XXHLS_LOAN_APPLICATION.TRANSACTION_ID%TYPE,
                                         i_schedule_type IN VARCHAR2)
    RETURN XXHLS_TYPES_PKG.t_ref_cursor
    IS
   
        UNDEFINED_SCHEDULE_TYPE EXCEPTION;
   
        l_loan_amount NUMBER DEFAULT 0;
        l_principal NUMBER DEFAULT 0;
        l_interest_rate NUMBER DEFAULT 0;
        l_glip_monthly_premium NUMBER DEFAULT 0;
        l_gdip_monthly_premium NUMBER DEFAULT 0;
       
    BEGIN
   
        SELECT  LOAN_AMOUNT, PAYMENT_AMOUNT, INTEREST_RATE
        INTO    l_loan_amount, l_principal, l_interest_rate
        FROM    XXHLS.XXHLS_LOAN_APPLICATION
        WHERE   TRANSACTION_ID = i_transaction_id;
       
        SELECT  PREMIUM_AMOUNT
        INTO    l_glip_monthly_premium
        FROM    XXHLS.XXHLS_INSURANCE_DETAILS
        WHERE   TRANSACTION_ID = i_transaction_id
                AND RATE_TYPE = 'GLIP';
               
        SELECT  PREMIUM_AMOUNT
        INTO    l_gdip_monthly_premium
        FROM    XXHLS.XXHLS_INSURANCE_DETAILS
        WHERE   TRANSACTION_ID = i_transaction_id
                AND RATE_TYPE = 'GDIP';
               
        IF i_schedule_type = 'MO1' THEN   
            RETURN generate_month_amort_sched_fn (l_loan_amount,
                                                  l_principal,
                                                  l_interest_rate,
                                                  l_glip_monthly_premium,
                                                  l_gdip_monthly_premium);
        ELSIF i_schedule_type = 'MO2' THEN
            RETURN NULL;
        ELSIF i_schedule_type = 'YRA' THEN
            RETURN NULL;
        ELSE
            RAISE UNDEFINED_SCHEDULE_TYPE;
        END IF;                                              
                                           
        RETURN NULL;                       
       
        EXCEPTION
            WHEN UNDEFINED_SCHEDULE_TYPE THEN
                DBMS_OUTPUT.PUT_LINE('undefined amortization schedule type');
                RETURN NULL;
            WHEN OTHERS THEN
                DBMS_OUTPUT.PUT_LINE(SQLERRM);
                RETURN NULL;
    END generate_amortization_sched_fn;