function foldAddComment () {
	var add_comment_title = document.getElementById('add_comment_title');
	var add_comment_field = document.getElementById('add_comment_field');
	if (add_comment_title && add_comment_field) {
		add_comment_title.style.backgroundPosition = 'bottom left';
		add_comment_field.style.display = 'none';
		add_comment_title.onclick = expandAddComment;
	}
	return false;
}

function expandAddComment () {
	var add_comment_title = document.getElementById('add_comment_title');
	var add_comment_field = document.getElementById('add_comment_field');
	if (add_comment_title && add_comment_field) {
		add_comment_title.style.backgroundPosition = 'top left';
		add_comment_field.style.display = 'block';
		add_comment_title.onclick = foldAddComment;
	}
	return false;
}

function checkFont (fontName) {
	var elem = document.getElementById('_checkFont_');
	if (!elem) {
		elem = document.createElement('span');
		elem.id = '_checkFont_';
		elem.style.visibility = 'hidden';
		elem.style.top = '-1000px';
		elem.style.left = '-1000px';
		elem.style.position = 'absolute';
		elem.innerHTML = 'あいうえおabcedfg';
		if (document.body) {
			document.body.appendChild(elem);
		}
	}
	elem.style.fontFamily = '_';
	var w = elem.offsetWidth;
	if (w == null) {
		w = document.defaultView.getComputedStyle(elem, '').width;
	}
	var h = elem.offsetHeight;
	if (h == null) {
		h = document.defaultView.getComputedStyle(elem, '').height;
	}

	elem.style.fontFamily = fontName;
	var nw = elem.offsetWidth;
	if (nw == null) {
		nw = document.defaultView.getComputedStyle(elem, '').width;
	}
	var nh = elem.offsetHeight;
	if (nh == null) {
		nh = document.defaultView.getComputedStyle(elem, '').height;
	}

	return w !== nw || h !== nh;
}

function changeFontSize (src) {
	if (!checkFont('メイリオ') || !checkFont('ヒラギノ角ゴ Pro W3')) {
		if (document.getElementsByTagName && document.createElement) {
			var link = document.createElement('link');
			var head = document.getElementsByTagName('head').item(0);
			link.rel = "stylesheet";
			link.type = "text/css";
			link.href = src;
			head.appendChild(link);
		} else {
			document.open();
			document.write('<link rel="stylesheet" href="' + src + '" type="text\/css">\n');
			document.close();
		}
	}
}