var min=8;
var max=30;
function increaseFontSize() {
   var div = document.getElementsByTagName('div')
   //alert(div[div.length-1;i++) {
   for(i=0;i<div.length;i++) {
      if(div[i].style.fontSize) {
         //var s = parseInt(div[i].style.fontSize.replace("px",""))
         var s = parseInt(div[i].style.fontSize.replace("pt",""))         
      } else {
         var s = 16
      }
      if(s!=max) {
         s += 1
      }
//alert(i)
       div[i].style.fontSize = s+"pt"
      
   }

}
function decreaseFontSize() {
   var div = document.getElementsByTagName('div');
   for(i=0;i<div.length;i++) {
      if(div[i].style.fontSize) {
         var s = parseInt(div[i].style.fontSize.replace("pt",""))
      } else {
         var s = 14
      }
      if(s!=min) {
         s -= 1
      }
      div[i].style.fontSize = s+"pt"
   }   
}