1.原数据：
2.想要将原数据转换成如下：


3.已编辑了code


DATA PROJECT1.BILLING_Jan_Dec;
SET WORK.SORTED_BILLING_ACCOUNTS;
BY BILLING_ACCOUNT;

RETAIN BILL_JAN  BILL_FEB  BILL_MAR  BILL_APR  BILL_MAY BILL_JUN BILL_JUL BILL_AUG BILL_SEP BILL_OCT BILL_NOV BILL_DEC;

if BILLING_ACCOUNT = 1 then do;
BILL_JAN =0;
BILL_FEB =0;
BILL_MAR =0;
BILL_APR =0;
BILL_MAY =0;
BILL_JUN =0;
BILL_JUN =0;
BILL_JUL =0;
BILL_AUG =0;
BILL_SEP =0;
BILL_OCT =0;
BILL_NOV =0;
BILL_DEC =0;
end;

IF BILL_MTH = '1JAN2011'D THEN DO;
        BILL_JAN = AMOUNT_TOPAY;
        END;
ELSE IF BILL_MTH = '1FEB2011'D THEN DO;
        BILL_FEB = AMOUNT_TOPAY;
        END;
ELSE IF BILL_MTH = '1MAR2011'D THEN DO;
        BILL_MAR = AMOUNT_TOPAY;
        END;
ELSE IF BILL_MTH = '1APR2011'D THEN DO;
        BILL_APR = AMOUNT_TOPAY;
        END;
ELSE IF BILL_MTH = '1MAY2011'D THEN DO;
        BILL_MAY = AMOUNT_TOPAY;
        END;
ELSE IF BILL_MTH ='1JUN2011'D THEN DO;
        BILL_JUN = AMOUNT_TOPAY;
        END;
ELSE IF BILL_MTH = '1JUL2011'D THEN DO;
        BILL_JUL = AMOUNT_TOPAY;
        END;
ELSE IF BILL_MTH = '1AUG2011'D THEN DO;
        BILL_AUG = AMOUNT_TOPAY;
        END;
ELSE IF BILL_MTH = '1SEP2011'D THEN DO;
        BILL_SEP = AMOUNT_TOPAY;
        END;
ELSE IF BILL_MTH = '1OCT2011'D THEN DO;
        BILL_OCT = AMOUNT_TOPAY;
        END;
ELSE IF BILL_MTH = '1NOV2011'D THEN DO;
        BILL_NOV = AMOUNT_TOPAY;
        END;
ELSE IF BILL_MTH = '1DEC2011'D THEN DO;
        BILL_DEC = AMOUNT_TOPAY;
        END;

IF LAST.BILLING_ACCOUNT = 1 THEN OUTPUT;

DROP BILL_MTH AMOUNT_TOPAY CREDIT_ADJ CURRENT_BILL_AMT LAST_BILL_AMT OUTSTANDING PAYMENT ROUNDING_AMT;
RUN;
4.结果和问题：

program出现了一个小感叹号

请问为什么会出现这种情况？代码我需要如何更改？