var bookurlArray = new Array();

bookurlArray[0] = "guestbook.en.php";
bookurlArray[1] = "guestbook.ja.php";
bookurlArray[2] = "guestbook.ru.php";
bookurlArray[3] = "guestbook.zh.php";

//-----------------------------------------------------------------------

function openBook( langindex ){
  
  if( langindex == -1 ){
    langindex = getlang();
  }
  
  var winwidth = document.body.clientWidth;
  var winheight = document.body.clientHeight;
  
  var option = "status=no,scrollbars=yes,width=550,height=650";
  var gburl =  bookurlArray[langindex];
  
  window.open( gburl, "guestbook", option );
}

//-----------------------------------------------------------------------