Steve:

Your statements below give you trouble:

call symput('height1',height);

%put 'height1='&height1;

The first call symput is executed when the data step encounters run statement and "%put 'height1='&height1;" tries to use the macro value before it is assigned. When you run the second time the macro value height1 exists and hence you may run without error.

I just gave you the cause. Without knowing what your intention, I cannot give you further help.

J S Huang 1-515-557-3987 fax 1-515-557-2422

>>> "Xiao, Steven" <sxiao@SFWMD.GOV> 2/28/2006 8:26:19 AM >>> SAS-L'ers -

To output the correct answer, I always have to run this Macro twice or more, whenever I invoke SAS and run this code, it gives me the error message as attached below, but I run it again, the correct answer will pop up, does anybody can help me out why and how to make it corrected?

Great thanks Env: WinXP with SAS-8

Steven

=========== Code ==============

%macro t();

data tmp;

set sashelp.class nobs=nobs;

if _N_=nobs

then

do;

call symput('height1',height);

%put 'height1='&height1;

put 'N=' _N_;

put 'nobs=' nobs;

end;

run;

quit;

%mend t;

%t;

=========== Code Finish ==============

============ Error when the 1st run ==============

1 %macro t();

2 data tmp;

3 set sashelp.class nobs=nobs;

4 if _N_=nobs

5 then

6 do;

7 call symput('height1',height);

8 %put 'height1='&height1;

9 put 'N=' _N_;

10 put 'nobs=' nobs;

11 end;

12 run;

13 quit;

14 %mend t;

15 %t;

WARNING: Apparent symbolic reference HEIGHT1 not resolved.

'height1='&height1

NOTE: Numeric values have been converted to character values at the places given by:

(Line):(Column).

1:96

N=19

nobs=19

NOTE: There were 19 observations read from the data set SASHELP.CLASS.

NOTE: The data set WORK.TMP has 19 observations and 5 variables.

NOTE: DATA statement used:

real time 0.10 seconds

cpu time 0.10 seconds

================= Error Finish ====================