var min=8;
var max=28;
function increaseFontSize(elements) {

   for(i=0;i<elements.length;i++) {
      if(elements[i].style.fontSize) {
         var s = parseInt(elements[i].style.fontSize.replace("pt",""));
      } else {
         var s = 12;
      } 
      
      if(s!=max) {
         s += 1;
      }
      elements[i].style.fontSize = s+"pt"
   }
}
function decreaseFontSize(elements) {

   for(i=0;i<elements.length;i++) {
      if(elements[i].style.fontSize) {
         var s = parseInt(elements[i].style.fontSize.replace("pt",""));
      } else {
         var s = 12;
      }
      if(s!=min) {
         s -= 1;
      }
      elements[i].style.fontSize = s+"pt"
   }   
}

function getElementsByClass(searchClass) {
 var classElements = new Array();
 var node = document;
 var tag = '*';
 var els = node.getElementsByTagName(tag);
 var elsLen = els.length;
 var pattern = new RegExp("(^|\\s)"+searchClass+"(\\s|$)");
 for (i = 0, j = 0; i < elsLen; i++) {
  if ( pattern.test(els[i].className) ) {
   classElements[j] = els[i];
   j++;
  }
 }
 return classElements;
}