function WriteCookie(key, value, days) {
   var str = key + "=" + escape(value) + ";";
   if (days != 0) {
      var dt = new Date();
      dt.setDate(dt.getDate() + days);
      str += "expires=" + dt.toGMTString() + ";";
   }
   document.cookie = str;
}
function ReadCookie(key) {
   var sCookie = document.cookie;
   var aData = sCookie.split(";");
   var oExp = new RegExp(" ", "g");
   key = key.replace(oExp, "");

   var i = 0;
   while (aData[i]) {
      var aWord = aData[i].split("=");
      aWord[0] = aWord[0].replace(oExp, "");
      if (key == aWord[0]) return unescape(aWord[1]);
      if (++i >= aData.length) break;
   }
   return "";
}
function DeleteCookie(key) 
{
   var dt = new Date();
   var str = key + "=;expires=" + dt.toGMTString();
   document.cookie = str;
}

//ユーザー設定項目
var defSize = 14; //規定サイズ
var Unit = 'px'       //単位
var chWidth = 2;  //増減幅
var days = 30;     //クッキー保存日数
//設定項目終わり

var x = defSize;
function SetFontSize(v)  {
   if (v > 10 && v < 300) { 
      document.body.style.fontSize = v + Unit;
      if (defSize == v)
         DeleteCookie('FontSize');
      else
         WriteCookie('FontSize', v, days);
      x = v;
   }
}
function FontSizeChange(cv) {
   if (cv == 0)
      SetFontSize(defSize);
   else
      SetFontSize(x + cv);
}
function ReadFontSize() {
   fs = ReadCookie('FontSize')
   if (fs != '') SetFontSize(fs);
}


//EOF