DatePicker Done button onclick

DatePicker Done button onclick

Hi - I have a DatePicker that displays Month/Year drop-down, I want to get the input field updated with mm/yyyy when the user click the "Done" button from the button panel

Tried to attach a click event but didn't work:
onOpen: function(){
button = $(this).datepicker('widget').find("button:contains('Done')");
                                button.click(function(){
                                                var month = $("##ui-datepicker-div .ui-datepicker-month :selected").val();
                                                var year = $("##ui-datepicker-div .ui-datepicker-year :selected").val();
                                                    $(this).datepicker('setDate', new Date(year, month, 1));
                                            });
},