$(document).ready(function () {
    $('.datepicker').each(function () {
        $(this).datepicker({
            dateFormat: "mm/dd/yy",
            changeYear: true,
            minDate: new Date('1900/01/01'),
            yearRange: 'c-50:c+50',
            defaultDate: '01/01/1980'
        });
    });
});