Hi Asmaaa, certainly you can do that by creating a Calculated Item called "Message". There is plenty of information of how to create calculated items in SAS MA User Guide.
In your case, your calculated item formula will be based on case statement (case when ... then ... when ... then ... else ... end);
Something like
case
when <<category>> = "Worker" and <<sex_client>> = "M" then "Dear Mr. " || <<Name of the client>> || ", good bye!"
when <<category>> = "Student" and <<sex_client>> = "F" then "Sorry we don't deal with female students, come back later, bye!"
else "Hey we don't know you, bye"
end
Hope it helps!
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Dmitriy Alergant, Tier One Analytics