function fontbt(mode,document_root){
	
	//フォントボタンの表示切り替え
	
	if (typeof(document_root) != "string"){
		document_root = "";
	}
	
	if (mode == "S"){
		document.font_s.src = document_root + "img/head/font_s_2.gif";
	}else{
		document.font_s.src = document_root + "img/head/font_s_1.gif";
	}
	
	if (mode == "M"){
		document.font_m.src = document_root + "img/head/font_m_2.gif";
	}else if(mode != "S" && mode != "M" && mode != "L"){
		document.font_m.src = document_root + "img/head/font_m_2.gif";
	}else{
		document.font_m.src = document_root + "img/head/font_m_1.gif";
	}
	
	if (mode == "L"){
		document.font_l.src = document_root + "img/head/font_l_2.gif";
	}else{
		document.font_l.src = document_root + "img/head/font_l_1.gif";
	}

	return null;
	
}

function fontbt_ini(document_root){
	//ページ読み込み時のボタン状態を設定
	fontbt(getActiveStyleSheet(),document_root);
}