Date Conversion problem ?

 Hi all,
            I am having a textbox which takes date from a calender control in the format ( mm/dd/yyyy) into the textbox . now this date is to be stored into three different textboxes i,e mm in box1 ,dd in box2 ,yyyy in box3 in the backend . Can any one say me how to convert this one textbox format to 3 different boxes format ..help plz
 
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