$(document).ready(function () {
 
    //min font size
    var min=9; 
 
    //max font size
    var max=16;
     
    //grab the default font size
    var reset = $('html,body,h1,h2,h3,p,a,img').css('fontSize');
     
    //font resize these elements
    var elm = $('html,body,h1,h2,h3,p,a,img'); 
     
    //set the default font size and remove px from the value
    var size = str_replace(reset, 'px', '');
     
    //Increase font size
    $('a.fontSizePlus').click(function() {
         
        //if the font size is lower or equal than the max value
        if (size<=max) {
             
            //increase the size
            size++;
             
            //set the font size
            elm.css({'fontSize' : size});
        }
         
        //cancel a click event
        return false;  
         
    });
 
    $('a.fontSizeMinus').click(function() {
 
        //if the font size is greater or equal than min value
        if (size>=min) {
             
            //decrease the size
            size--;
             
            //set the font size
            elm.css({'fontSize' : size});
        }
         
        //cancel a click event
        return false;  
         
    });
     
    //Reset the font size
    $('a.fontReset').click(function () {
         
        //set the default font size
         elm.css({'fontSize' : reset});    
    });
         
});
 
//A string replace function
function str_replace(haystack, needle, replacement) {
    var temp = haystack.split(needle);
    return temp.join(replacement);
}