function set_font_size(id) {
	var b_elm = document.getElementById('FontBig');
	var s_elm = document.getElementById('FontSmall');
	var b_src = b_elm.getAttribute('src');
	var s_src = s_elm.getAttribute('src');

	switch (id) {
		case 'FontBig':
			document.getElementById('Main').style.fontSize = "116%";
			b_elm.setAttribute('src', b_src.replace('_base', '_flip'));
			s_elm.setAttribute('src', s_src.replace('_flip', '_base'));
			break;
		case 'FontSmall':
			document.getElementById('Main').style.fontSize = "96%";
			b_elm.setAttribute('src', b_src.replace('_flip', '_base'));
			s_elm.setAttribute('src', s_src.replace('_base', '_flip'));
			break;
		default:
			break;
	}
}

/**
 *
 * 画像切り替え
 *
**/
function smartRollover(base, flip) {
  var imgs = document.images;
  if (!document.images) {
    return false;
  }
  var pre = new Array();
  for (var i = 0; i < imgs.length; i++) {
    var src = imgs[i].src;
    if (src.match(base)) {
      // 画像先読み
      pre[i] = new Image();
      pre[i].src = src.replace(base, flip);

      // ロールオーバー設定
      imgs[i].onmouseover = function() {
        this.src = this.src.replace(base, flip);
      }
      imgs[i].onmouseout = function() {
        this.src = this.src.replace(flip, base);
      }
    }
  }
}

/**
 *
 * イベント追加
 *
**/
function addEvent(elm, eventName, func) {
  if (elm.addEventListener) {
    elm.addEventListener(eventName, func, false);
    return true;

  } else if (elm.attachEvent) {
    elm.attachEvent("on"+eventName, func);
    return true;

  } else {
    return false;

  }
}


/**
 *
 * 別窓オープン
 *
**/
function external() {
	if (!document.getElementsByTagName) {
		return;
	}
	var anchors = document.getElementsByTagName('a');
	for (var i = 0; i < anchors.length; i++) {
		var anchor = anchors[i];
		if (anchor.getAttribute('class') == 'external' || anchor.getAttribute('className') == 'external') {
			anchor.setAttribute('target', '_blank');
		}
	}
}

addEvent(window, 'load', function(){smartRollover('_off.', '_on.');});
addEvent(window, 'load', external);