[jQuery] Multiple elements slider

Hi,
I have one slider that have to resize font-size on 4 different
elements. At this time it works on all 4 of them (span) but I would
like to make it work for any individual element that is selected. If I
select one element the slider should resize only that one.

My slider code is:

        // Font Size Slider
        $().ready(function() {
            document.onselectstart = new Function('return false');

            /* simple slider[default skin] */
            var maxFont = 60;
            var mf = $('span).css('font-size', 20);
                //       var mf = $('span').attr('title');

            $.fn.jSlider({
                renderTo: '#slidercontainer1',
                size: { barWidth: 400, sliderWidth: 5 },
                onChanging: function(percentage, e) {
                    mf.css('font-size', maxFont * percentage);
                    window.console && console.log('percentage: %s',
percentage);
                }

            });
            });

Thank you for your help!