Change the class of date randomly in Keith wood datepick

Change the class of date randomly in Keith wood datepick

Hi,

 I am using keith wood datepick calendar. My requirement is  i have to set budget on some dates, as i entered the budget on text box i wanted to mention that budget bottom of that perticular date on the datepick open calendar. I worked it using   
onDate: function (date, inMonth) { content: date.getDate() + '<br><sub>$56</sub>'}, 
but this will work only when datepick will load at the time of loading page. but now i want it to fly as i do the changes on text box it should mention on datepick without loading datepick (whole calendar).

Any help ?