(Note: The change caused by this menu option is only 
visible by opening another hypertext file or by using 
a jump link to another file.)

The "Underline Hot Text" menu option sets a flag
which is used by the OnHandleShowHotLine method 
of the HTDisplayBox component. This method is used 
to affect final display properties of hot text 
(in this case by italicizing it.) Other changes 
could include the contents of the text or its font 
and color.

(Note: Assert methods normally are used to abort
all further processing of an action, while the
Handle Methods modify the processing. These
two methods can each be overridden in code by
direct assignment for Assert types and virtual
overriding for Handle types.)

