How to set global onSelect event on all datepickers?

How to set global onSelect event on all datepickers?

Hi,

I am trying to set global onSelect event on datepicker using setDefaults method, but without success.  Below the code I use:

jQuery.datepicker.setDefaults({
   showOn: 'both',
   onSelect:function(){alert(2)},
   buttonImageOnly: true,
   buttonImage: 'calendar.gif',
   buttonText: 'Calendar' });


When I am trying to set onSelect on single element it is work perfect.
But I need to do it globally.

Thank you for help.