Help with datepicker minDate

Help with datepicker minDate

How do I set the minDate of a datepicker to be the original value in the text box it's attached to, at the time that the datepicker is created?

Consider the following code:
Everything works as expected, except that the minDate isn't being set, apparently.
  1. $(".updateabledate").datepicker({
                        dateFormat: 'M dd, yy',
                        minDate: new Date($(this).attr("value")),
                        showAnim: 'drop',
                        onSelect: function(input, inst){
                            $(this).siblings(".btnSaveDate").show();
                        }
                    });