procedure
                        :optionbutton           name

Creates an optionbutton widget within the current panel frame for the TCL
interpreter. An optionbutton widget is a button window.  A list of options is
associated with the widget and the currently selected option is displayed
within the button window.  Items from the option list are selected cyclically
using the mouse.
name is used to generate the path name of the window to be created. It
should have the format of a widget name  (e.g.  :optionbutton  OPT) and
should be unique within this interpreter. The name will be lower-cased (using
the string tolower command) in order to generate the path name used to
create the window.
When the button is selected using the mouse then ,if available, the TCL script
supplied using the :command parameter will be executed. If this is not
available the TCL command
click  FRAME “ ” OPTIONBUTTON  index option
will be executed where FRAME and OPTIONBUTTON are widget names,
index is the index (from zero) into the option list of the current option and
option is the current option.
The path name generated has the form framename.panelname.buttonname.
The :optionbutton procedure may also be used directly within a frame window (i.e. before
any panel window has been created).


The :optionbutton procedure may have a number of arguments however
none of these is mandatory.

        arguments
                        :x                      number
        number is the x-co-ordinate within the current panel of the optionbutton
widget in pixels
        e.g.    :x 400

                        :y                      number
        number is the y-co-ordinate within the current panel of the optionbutton
widget in pixels
        e.g.    :y 200
The :x and :y parameters may be omitted in which case the packer geometry manager will be
used and the position of the window will be determined by the contents of the master (panel)
window. If however the :x and :y parameters are supplied then the placer geometry manager
will be used to position the window within the master (panel) window.
Warning:        Note that it is not possible to mix use of the packer and placer geometry
managers within the same window. Thus all windows within a panel must request or imply that
the same geometry manager is used.


                        :w                      number
        number is the width of the optionbutton window in characters.
        e.g.    :w   20

                        :h                      number
        number is the height of the optionbutton window in lines of text.
        e.g.    :h   2
The :w and/or :h parameters may be omitted in which case the size of the optionbutton will be
determined by its contents. If however the :w and :h parameters are supplied then these will
be used to configure the button window. Normally :h will not be supplied.

                        :value                  value
        value is the index of the default option item within the option list.
The default value is 0.

                        :strings                list
        list is a simple TCL list of text strings which form the elements of the
option list.
The default is a null list and hence an empty option list. :menu is an alias for :strings.

                        :command                string
        string is any TCL command or commands to be executed when an
event is generated.
If a command is supplied and executed in this manner then the click procedure is not invoked

See also common procedure arguments defined later in this document.