Simple autocomplete / typeahead widget.
Keyboard and mouse commands are as follows:
When focused in text input box:
arrows move focus to suggestion list
alphanumerics and backspace display suggestion list if matches found
(count of matches is displayed if "show screen reader messages" is checked in the demo)
When focused in suggestions list:
arrows and/or mouse hover move focus among suggestions
(if in single select mode, selection follows focus, otherwise selection does not change)
enter and/or mouse click accepts current selection and closes list
(if in single select mode will select item, otherwise selection not modified)