var minFont=11;
var maxFont=15;
var fontMinusName = 'fontminus';
var fontPlusName = 'fontplus';
var buttonPlusActive = '/images/font_resize/butt_plus1.gif';
var buttonPlusInactive = '/images/font_resize/butt_plus2.gif';
var buttonMinusActive = '/images/font_resize/butt_minus1.gif';
var buttonMinusInactive = '/images/font_resize/butt_minus2.gif';
var divOfText  = "articlecontent";

if (!currentSize) // no found, read from cookie, no cookie, get from base value
{
  var cookieSize = 0;
  var currentSize = '0';
  cookieSize = getCookie('currentSize');
  if (cookieSize <=0) 
  {
    currentSize = '11px'; //base value, remove hardcoding by referencing a known element font size.
  }else 
  {
    currentSize = cookieSize;
  }
  var s = parseInt(currentSize.replace("px",""),10);
  setFontSize(s);
}

function increaseFontSize() {
  var s = parseInt(currentSize.replace("px",""),10);
  if (s < maxFont) 
  { s+=1; }
  setFontSize(s);
}

function decreaseFontSize() {
   var s = parseInt(currentSize.replace("px",""),10);
   if (s > minFont) 
   { s-=1; }
   setFontSize(s);
}

function setFontSize(newSize)
{
  var p = document.getElementById(divOfText);
  p.style.fontSize = newSize+"px";
  var lineHeight = newSize *1.3;
  p.style.lineHeight = lineHeight+"px";
  currentSize = newSize+"px";
  setCookie('currentSize',newSize,60);
  if (newSize==minFont)
  {
    document[fontMinusName].src = buttonMinusInactive;
  }
  else
  {
	document[fontMinusName].src = buttonMinusActive;
  }
  if (newSize==maxFont)
  {
    document[fontPlusName].src = buttonPlusInactive;
  }
  else
  {
	document[fontPlusName].src = buttonPlusActive;
  }
}

function setCookie(c_name,value,expiredays)
{
  var exdate=new Date();
  exdate.setDate(exdate.getDate()+expiredays);
  document.cookie=c_name+ "=" +escape(value)+
    ((expiredays==null) ? "" : ";expires="+exdate.toGMTString());
}
 
function getCookie(c_name)
{
  if (document.cookie.length>0)
  {
    c_start=document.cookie.indexOf(c_name + "=");
    if (c_start!=-1)
    { 
      c_start=c_start + c_name.length+1; 
      c_end=document.cookie.indexOf(";",c_start);
      if (c_end==-1) c_end=document.cookie.length;
      return unescape(document.cookie.substring(c_start,c_end));
    } 
  }
  return 0;
}