move the mouse onto that text, Emacs displays that string in the echo
area, or in the tooltip window.
-If the value of the @code{help-echo property} is a function, that
+If the value of the @code{help-echo} property is a function, that
function is called with three arguments, @var{window}, @var{object} and
-@var{position} and should return a help string or nil for
+@var{position} and should return a help string or @var{nil} for
none. The first argument, @var{window} is the window in which
the help was found. The second, @var{object}, is the buffer, overlay or
string which had the @code{help-echo} property. The @var{position}
the mouse.
@item
If @var{object} is a string (an overlay string or a string displayed
-with the @code{display} property) @var{pos} is the position in that
+with the @code{display} property), @var{pos} is the position in that
string under the mouse.
@end itemize
If the value of the @code{help-echo} property is neither a function nor
a string, it is evaluated to obtain a help string.
-Variable @code{show-help-function} (@pxref{Help display}) provides a
-hook to alter the way help text is displayed.
+You can alter the way help text is displayed by setting the variable
+@code{show-help-function} (@pxref{Help display}).
This feature is used in the mode line and for other active text. It is
available starting in Emacs 21.
@defvar show-help-function
@tindex show-help-function
-@anchor{Help display}
-If this variable is non-@code{nil} it specifies a function called to
-display help strings. These may be @code{help-echo} properties or menu
-(@pxref{Simple Menu Items}, @pxref{Extended Menu Items}) or tool bar
-(@pxref{Tool Bar}) help strings. The specified function is called with
-one argument, the help string to display. Tooltip mode
-(@pxref{(emacs)Tooltips}) provides an example.
+@anchor{Help display} If this variable is non-@code{nil}, it specifies a
+function called to display help strings. These may be @code{help-echo}
+properties, menu help strings (@pxref{Simple Menu Items},
+@pxref{Extended Menu Items}), or tool bar help strings (@pxref{Tool
+Bar}). The specified function is called with one argument, the help
+string to display. Tooltip mode (@pxref{(emacs)Tooltips}) provides an
+example.
@end defvar
@node Format Properties