AJAX Web interface to schedule Quartz jobs

Create a single XHTML+CSS+JavaScript web page to construct Quartz scheduled job schedule specifications.

The XHTML page should have a single text form field named "schedule", which is designed to accept a job schedule specification according to the documentation at http://www.quartz-scheduler.org/docs/tutorials/crontrigger.html. The `schedule` field can be populated one of three ways.

1) Manually. If the user knows the format (or wants to follow the spec), he can enter anything he wants into the `schedule` field. A button should be provided that calls a JavaScript function that validates the `schedule` field against the specification and displays whether it is valid or not.
2) Select from a drop down list of common options. A list of common options will be provided as a drop-down. If the user selects from this drop down, the `schedule` field will be replaced with the appropriate specification. For the purposes of this project, the following three schedules should be available: {'daily': '0 0 0 * * ?', 'hourly': '0 0 * * * ?', 'monthly': '0 0 0 1 * ?'}.
3) Constructed through a web form. An additional web interface will be provided to visually construct the schedule. This should be a purely client-side form that uses the web controls to construct a valid Quartz schedule. For an example of what the form might look like, consider the Webmin cron job scheduler, attached. JavaScript included in the page will interpret the form selections and produce the proper schedule in the `schedule field`. The advanced web form should be visually hidden unless a link "Advanced Schedule" is clicked.

The form should behave reliably even if more than one mechanism is used. In other words, if the user alters the text manually, the advanced form should match the schedule or otherwise be disengaged. The user should then be able to re-engage the advanced form to customize or override the manual entry.

The final project should include readable and maintainable JavaScript, preferably in a separate file included from the XHTML. The page may also include some basic CSS for styling.

The page should work reliably under both IE8 and Firefox 3.5.