+The MasterKey Widget Set can be invoked as a jQuery plugin rather than
+by providing an HTML skeleton explicitly. When this approach is used,
+the invocation is a single line of JavaScript:
+
+ <script>jQuery.pazpar2();</script>
+
+This code should be inserted in the page at the position where the
+metasearch should occur.
+
+When invoking this plugin, a hash of named options may be passed in to
+modify the default behaviour, as in the exaple above. The available
+options are as follows:
+
+---
+Element Type Default Description
+-------- ----- --------- ------------
+layout string popup Specifies how the user interface should
+ appear. Options are `table` (the default,
+ with facets at the bottom), `div` (with
+ facets at the side) and `popup` (to
+ obtain a popup window).
+
+width int 880 Width of the popup window (if used), in
+ pixels.
+
+height int 760 Height of the popup window (if used), in
+ pixels.
+
+id_button string input#mkwsButton (Never change this.)
+
+id_popup string #mkwsPopup (Never change this.)
+---
+
+Note that when using the `popup` layout, facilities from the jQuery UI
+toolkit are used, so it's necessary to include both CSS and JavaScript
+from that toolkit. The relevant lines are:
+
+ <script src="http://code.jquery.com/ui/1.10.3/jquery-ui.min.js"></script>
+ <link rel="stylesheet" type="text/css" href="http://code.jquery.com/ui/1.10.3/themes/smoothness/jquery-ui.css" />
+