@begin(header)
author: Eric Mandel
show_author: ShowNone
author_organization: Smithsonian Astrophysical Observatory
node_expert: eric@cfa.harvard.edu
expiration_date: 12/31/93
last_modifier: eric@cfa.harvard.edu
last_mod_date: 11/13/92
mod_num: 2
@end(header)
@b<This window tells you how to change parameter values using the parameter editor.>

The @b<parameter editor> can be used to display and edit parameters,
run tasks, display help, and ask questions.  The @b<parameter editor>
consists of two parts: the command strip and the parameter section.

The parameter section displays the parameter name, mode, value, min,
max, and prompt string. In addition, a highlighted arrow points to all
non-hidden parameters, as a reminder that these parameters should be
explicitly set.  Name and mode are read only, while the other values
can be edited.  (This can be changed. See below).  To edit a parameter
value, simply place the mouse over the value (a border will appear
outlining the value) and use emacs-style commands to edit.  If a <CR>
is entered, the new parameter value is updated by sending that value
to the IRAF window. The mouse is then moved to the next parameter.
Alternatively, the parameters can be updated with the "Update" or
"Run" commands.  The control keys ^N and ^P will move the mouse
to the next and previous widget, respectively.

As is the case of the IRAF @b<eparam> task, parameter values are
checked against the current min and max values. Boolean parameters can
be "yes", "y", "no", or "n".  If an incorrect value is entered, a
@b<try-again window> will pop up describing the problem and requesting
a new value.

Immediate help for a parameter can be obtained by clicking the
@b<middle> mouse button on the parameter name.  The action then taken
depends on the value of the @b<usexih> resource.  If this resource is
set to "False", an IRAF help file will be brought up in a separate
window, and the parameter in question will be highlighted.  If the
parameter in question cannot be found, a search window is activated,
allowing the user to perform his own search.  If set to "True", a
separate window will be brought up containing help for the specified
parameter.  The default is to use the latter method.

If the @b<right> mouse button is clicked on a pset parameter value,
the parameter editor for that pset is activated.  Also, if the
@b<right> mouse button is clicked on an indirect parameter value,
the indirect value of that parameter is displayed.  These are the only
uses of the @b<special> mouse button defined thus far.

To learn more about parameter commands:
@button<Param Commands, Param_Commands>