The subject of macros is reasonably complex (but well worth learning) please ensure you have at least read the macro introduction before reading this section.
Also note that you can create a macro which accepts
optional parameters. The "VISIBLE" parameter we have been using
up to now is manditory (required), if not supplied the preprocessor
will inform you of this fact and stop. To make a parameter optional you
assign at least the first occurance of the parameter
a default value. You can give each occurance a default value (which
may be different), and the last specified default value is remembered for
subsequent occurances where a default value is required but not
specified. For example to change the
email macro to use my email address as the default but allow the
specification of alternative addresses I could do the following:
#define EmailMeLink <A HREF="mailto:{$EMAIL='db0@anz.com'}">{$VISIBLE}</A>
You could then say:
<P>If you have any questions or suggestions for improvements please feel free to
<$EmailMeLink VISIBLE=@email me@>, I have another
<$EmailMeLink VISIBLE=@email address@ EMAIL=$db1@anz.com$> which
you might like to try.