// JavaScript Document

var min=10;
var max=13;
function increaseFontSize() {
   var body = document.body;
   if(body.style.fontSize) {
      var s = parseInt(body.style.fontSize.replace("px",""));
   } else {
      var s = min;
   }
   if(s!=max) {
      s += 1;
   }
   body.style.fontSize = s+"px";

}
function decreaseFontSize() {
   var body = document.body;
   if(body.style.fontSize) {
      var s = parseInt(body.style.fontSize.replace("px",""));
   } else {
      var s = min;
   }
   if(s!=min) {
      s -= 1;
   }
   body.style.fontSize = s+"px";
      
}