var min=8;
var max=18;
function increaseFontSize() {
   var p = document.getElementsByTagName('font');
   for(i=0;i<p.length;i++) {
      if(p[i].style.fontSize) {
         var s = parseInt(p[i].style.fontSize.replace("px",""));
      } else {
         var s = 12;
      }
      if(s!=max) {
         s += 1;
      }
      p[i].style.fontSize = s+"px"
   }
}
function decreaseFontSize() {
   var p = document.getElementsByTagName('font');
   for(i=0;i<p.length;i++) {
      if(p[i].style.fontSize) {
         var s = parseInt(p[i].style.fontSize.replace("px",""));
      } else {
         var s = 12;
      }
      if(s!=min) {
         s -= 1;
      }
      p[i].style.fontSize = s+"px"
   }   
}


// This script will change the font size of any text within a paragraph (<p>  tag).
//If you wish to change text within other tags edit the getElementsByTagName('p'); part.
//In order for this code to work your page must be using pixel sized fonts (px) rather
//than relative sized fonts using 'em' or '%'. Of course if you do use other font units
//the code can be easily adapted for these. If the script cannot find the font size of
//a paragraph it will default it to 12px.-->