audioをplay, pauseするfunctionの中で、playしているli要素をboldにして、textContentで渡せばいいだけですね♪♪♪
<h2>Catcher In The Light<div style="display:inline;" id="title"></div></h2> <p><audio src="/mp3/180307112410.mp3" preload="none" onclick="playthis(1);" controls="controls"></audio></p> <ul> <li id="list1"><a href="javascript:playthis(1)">Catcher In The Light</a></li> <li id="list2"><a href="javascript:playthis(2)">About You</a></li> <li id="list3"><a href="javascript:playthis(3)">GAME</a></li> <li id="list4"><a href="javascript:playthis(4)">my name's WOMEN</a></li> <li id="list5"><a href="javascript:playthis(5)">WONDERLAND</a></li> </ul> <script type="text/javascript"> var dir = "/foo/"; // var now = " ← now playing"; var media = document.getElementsByTagName("audio")[0]; var list = new Array(5); list[1] = "hoge.mp3"; list[2] = "hogehoge.mp3"; list[3] = "hogehogehoge.mp3"; list[4] = "hogehogehogehoge.mp3"; list[5] = "hogehogehogehogehoge.mp3"; var length = list.length; var COOKIE = new Array(); if (document.cookie) { var cookies = document.cookie.split("; "); for (var i = 0; i < cookies.length; i++) { var str = cookies[i].split("="); COOKIE[str[0]] = unescape(str[1]); } } var volume = isNaN(COOKIE["volume"]) ? 0.5 : COOKIE["volume"]; media.volume = volume; media.onended = function(){ playnext(this.src); }; window.onbeforeunload = function(){ setCookie("volume", media.volume); }; </script> <script type="text/javascript"> function playthis(key){ media.pause(); media.src = dir + list[key]; media.play(); var hoge =list[key]; var tag = document.getElementById("list"+key).innerHTML; var title = tag.replace(/<("[^"]*"|'[^']*'|[^'">])*>/g,''); var song = document.getElementById("title"); song.textContent = " : " + title; // for(var i=1;i<length;i++) document.getElementById("list"+i).innerHTML = document.getElementById("list"+i).innerHTML.replace(now,""); for(var i=1;i<length;i++) document.getElementById("list"+i).style.fontWeight = "normal"; document.getElementById("list"+key).style.fontWeight = "bold"; // document.getElementById("list"+key).innerHTML += now; } function playnext(objsrc) { var objsrc = decodeURI(objsrc); objsrc = objsrc.replace("http://"+location.host,""); for (var i=1;i<length;i++) { var listsrc = dir + list[i]; if(objsrc===listsrc){ if(length==i+1){ document.getElementById("list"+i).innerHTML = document.getElementById("list"+i).innerHTML.replace(now,""); // 先頭を再生 // playthis(1); }else{ playthis(i+1); } break; } } } function setCookie(name, value, domain, path, expires, secure) { if (!name) return; domain = location.hostname; path = "/"; expires = 30; var str = name + "=" + escape(value); if (domain) { if (domain == 1) domain = location.host.replace(/^[^\.]*/, ""); str += "; domain=" + domain; } if (path) { if (path == 1) path = location.pathname; str += "; path=" + path; } if (expires) { var nowtime = new Date().getTime(); expires = new Date(nowtime + (60 * 60 * 24 * 1000 * expires)); expires = expires.toGMTString(); str += "; expires=" + expires; } if (secure && location.protocol == "https:") { str += "; secure"; } document.cookie = str; } </script>