请教：初学sas，以下是我写的程序：
%macro a(fyear,seller_industry);
data b;
set tran_info;
if &fyear;
if &seller_industry;
%mend a;
%a("2000",C03);
run;

我是想将tran_info根据fyear和seller_industry值的不同放在表b里面，%a("2000","C03");是想将fyear为2000年，seller_industry为C03的提出来，但程序运行后， 提示：NOTE: Character values have been converted to numeric values at the places given by:      (Line):(Column).
      1:2
NOTE: Variable C03 is uninitialized.
NOTE: There were 758 observations read from the data set WORK.TRAN_INFO.
NOTE: The data set WORK.B has 0 observations and 25 variables.
这到底是错哪里了？谢谢解惑！