Disabling ComponentArt Calendar

I had a hard time figuring out how to enable and disable the ComponentArt calendar control from javascript. This bit of code is for the picker/popup calendar combination as seen here. 

var disabled = ...;

// The button isn't a server control, so it has a static Id
document.getElementById('scheduledDateCalendar_button').disabled = disabled;
document.getElementById('<%=this.scheduledDate.ClientID %>_picker').disabled = disabled;

The dom element written by the server which corresponds to the picker control has _picker appended to the client ID. Once you know this it's easy to disable that element.