// load the drop-down button code
var at_code;
if (document.location.protocol == "https:")
    at_code = '<script src="https://secure.addthis.com/js/250/addthis_widget.js#username=nsbi" type="text/javascript"></script>';
else
    at_code = '<script src="http://s7.addthis.com/js/250/addthis_widget.js#username=nsbi" type="text/javascript"></script>';
document.writeln(at_code);