var GL_Style = "normalStyle";

// --------------------------------------------------------------------------------
function decreaseFontSize()
{
   var styleCookie = getCookie("fontSize");
   switch (styleCookie)
   {
      case "xx-largeStyle":
          styleID = "x-largeStyle";
          break;
      case "x-largeStyle":
         styleID = "largeStyle";
         break;
      case "largeStyle":
          styleID = "normalStyle";
          break;
      case "normalStyle":
          styleID = "normalStyle";
          break;
     default:
         styleID = "normalStyle";
         break;
   }
   setCookie("fontSize", styleID, getExpDate(365, 0, 0));
   setSizeStyle();
}

// Input values:
// name - name of the cookie
// [path] - path of the cookie (must be same as path used to create cookie)
// [domain] - domain of the cookie (must be same as domain used to create cookie)
// * path and domain default if assigned null or omitted if no explicit argument proceeds
function deleteCookie(name, path, domain) {
  if (getCookie(name)) {
    document.cookie = name + "=" + 
    ((path) ? "; path=" + path : "") +
    ((domain) ? "; domain=" + domain : "") +
    "; expires=Thu, 01-Jan-70 00:00:01 GMT";
  }
}

// Input value:
// name - name of the desired cookie
// * return string containing value of specified cookie or null if cookie does not exist
function getCookie(name) {
  var dc = document.cookie;
  if (dc == "" || dc == null)
     return (GL_Style);
  else
  {
     var prefix = name + "=";
     var begin = dc.indexOf("; " + prefix);
     if (begin == -1) {
       begin = dc.indexOf(prefix);
       if (begin != 0) return null;
     } else
       begin += 2;
     var end = document.cookie.indexOf(";", begin);
     if (end == -1)
       end = dc.length;
     return unescape(dc.substring(begin + prefix.length, end));
   }
}

function getExpDate(days, hours, minutes)
{
   var expDate = new Date();
   if (typeof days == "number" && typeof hours == "number" && typeof minutes == "number"  )
   {
       expDate.setDate(expDate.getDate() + parseInt(days));
       expDate.setHours(expDate.getHours() + parseInt(hours));
       expDate.setMinutes(expDate.getMinutes() + parseInt(minutes));
       return expDate.toGMTString();
   }
}

// Input values:
// name - name of the cookie
// value - value of the cookie
// [expires] - expiration date of the cookie (defaults to end of current session)
// [path] - path for which the cookie is valid (defaults to path of calling document)
// [domain] - domain for which the cookie is valid (defaults to domain of calling document)
// [secure] - Boolean value indicating if the cookie transmission requires a secure transmission
// * an argument defaults when it is assigned null as a placeholder
// * a null placeholder is not required for trailing omitted arguments
function setCookie(name, value, expires, path, domain, secure) {
    var curCookie = name + "=" + escape(value) +
        ((expires) ? "; expires=" + expires : "") +
        "; path=/" + 
        ((domain) ? "; domain=" + domain : "") +
        ((secure) ? "; secure" : "");
    document.cookie = curCookie;
    GL_Style = value;
    return(true);
}

function increaseFontSize()
{
   var styleCookie = getCookie("fontSize");

   switch (styleCookie)
   {
      case "normalStyle":
         styleID = "largeStyle";
         break;
      case "largeStyle":
          styleID = "x-largeStyle";
          break;
      case "x-largeStyle":
          styleID = "xx-largeStyle";
          break;
      case "xx-largeStyle":
         styleID = "xx-largeStyle";
         break;
     default:
         styleID = "normalStyle";
         break;
   }
   setCookie("fontSize", styleID, getExpDate(365, 0, 0));
   setSizeStyle();
}


function setSizeStyle()
{
  if (document.getElementById)
  {
      var styleIDs = ["normalStyle", "largeStyle", "x-largeStyle", "xx-largeStyle"];
      var idx;
       var styleCookie = getCookie("fontSize");
       if (styleCookie == "" || styleCookie == null) 
       {
          styleCookie = "normalStyle";
          setCookie("fontSize", styleCookie, getExpDate(365, 0, 0));
      }
      for (var idx=0; idx < styleIDs.length; idx++)
      {
         if (styleCookie == styleIDs[idx]) 

            document.getElementById(styleIDs[idx]).disabled = false;
         else
            document.getElementById(styleIDs[idx]).disabled = true;
      }
  }
}