You can use macros to control conditional execution
of statements. Remember the example from the beginning of this chapter
where you wanted to run a daily report to create registration listings
for courses to be held later in the month. Remember that you also
wanted to run a weekly report each Friday to create a summary of revenue
that has been generated so far in the current month. You can accomplish
these tasks with one program if you use conditional execution to determine
whether the second report should be run.
You can perform conditional
execution at the macro level with %IF-%THEN and %ELSE statements.
General form, %IF-%THEN
and %ELSE statements:
%IF expression %THEN text ...