$(document).ready(function(){

    (function(){
        var sizer = $("<li id='text-size'><span>Text size:</span><a class='decrease' href='#'>Decrease text size</a><a class='increase' href='#'>Increase text size</a></li>");

        sizer.appendTo('#mainnav .primary ul');

        var textMin = 12,
        textMax = 18,
        body = $('body');

        $('.decrease').click(function(){
            current = parseFloat(body.css('fontSize'),10);
            newsize = Math.max(current-1,textMin);
            body.css('font-size',newsize);
        });

        $('.increase').click(function(){
            current = parseFloat(body.css('fontSize'),10);
            newsize = Math.min(current+1,textMax);
            body.css('font-size',newsize);
        });

    })();

});