Mary's response is correct. But you can change it.
Some things for you to note:
Use our web design forum for your web publication issues.
Bookmark the FAQ -
http://www.publishermvps.com/WebDesign/FAQ/tabid/30/ItemId/134/Default.aspx -
and refer to it.
Note that your question is on said FAQ and look at what you'd find on it
(pasted below since I'm in a good mood) - last sentence ...
A.
One of the most important things to remember when designing a web page is
that you should only use the standardized "web safe" fonts. If you use a font
other than one of the 8 web safe fonts then your site visitor may view your
content in a font their browser substitutes. That result can be
unpredictable. To avoid that 'mistake' the web publication only allows the
appropriate fonts.
The 8 web safe fonts are: Arial, Comic Sans, Courier, Georgia, Impact, Times
New Roman, Trebuchet, Verdana.
If you opt to ignore this web safe design you can disengage the safe font
setting. In a web publication go to Format, Font, and deselect the "show only
web font" option. Then all fonts on the system will be available.