How would I duplicate making a portion of the where clause of a procedure change depending upon what value was passed to th procedure? In vfp I could use the macro substitution and do the following:

If empty(x)
whereclause = ' .t.'
else
whereclause = ' x = y'
endif

select * from tablea where b=c and &whereclause

How would I duplicate this in my stored procedure with out making the select statement twice?

Thanks in advance
Kelly