点击标题，内容切换代码，急！！！

<div class="b1">标题1</div>
<div class="b2">标题1</div>
<div class="n1">标题1的内容</div>
<div class="n2">标题2的内容</div>
实现的效果是点击标题1，出现标题1的内容，点击标题2出现标题2的内容，默认情况下是出现标题1的内容。那位有比较简洁的这种切换js代码，急！

解决方案 »

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function check(){
var n1 = document.getElementById("n1");
if(a.style.display=="block")
    document.getElementById("n1").style.display="none";//隐藏
else
   document.getElementById("n1").style.display="block";//显示
}
<script>
function doClick(obj){
  alert(obj.innerText);
}
</script>
<div class="b1" onclick="doClick(this);"> 标题1 </div>
<div class="b2" onclick="doClick(this);"> 标题1 </div>
<div class="n1" onclick="doClick(this);"> 标题1的内容 </div>
<div class="n2" onclick="doClick(this);"> 标题2的内容 </div>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312" />
<title>bbs</title>
<style type="text/css">

</style>
</head>
<body>
<script language=javascript>
function secBoard(n)
{
for(i=0;i<menu.childNodes.length;i++)
menu.childNodes[i].className="sec1";
menu.childNodes[n].className="sec2";
for(i=0;i<main.childNodes.length;i++)
main.childNodes[i].style.display="none";
main.childNodes[n].style.display="block";
}
</script>
<div id="header">
<ul id="menu">
<li onMouseOver="secBoard(0)" class="sec2">技术篇</li>
<li onMouseOver="secBoard(1)" class="sec1">生活篇</li>
<li onMouseOver="secBoard(2)" class="sec1">个人资料</li>
<li onMouseOver="secBoard(3)" class="sec1">斑竹管理</li>
</ul>

<ul id="main">
<li class="block">第一个内容dddddddddddddddddd</li>
<li class="unblock">第二个内容</li>
<li class="unblock">第三个内容</li>
<li class="unblock">第四个内容</li>
</ul>

</div>
</body>
</html>
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<html>
<style type="text/css">
div{cursor:hand;}
</style>
<script language="javascript" for="window" event="onload">
document.getElementById("test").innerHTML=document.getElementById("b1").innerHTML
</script>
<script type="text/javascript">
function test(obj)
{
    document.getElementById("test").innerHTML="";
    var dd=document.getElementById(obj);
    document.getElementById("test").innerHTML=dd.innerHTML;
}
</script>
<body>
    <div class="b1" id="b1" onclick="test('b1');">标题1</div>
    <div class="b2" id="b2" onclick="test('b2');">标题2</div>
    <div class="n1" id="n1" onclick="test('n1');">标题1的内容</div>
    <div class="n2" id="n2" onclick="test('n2');">标题2的内容</div>
    <div id="test" style="color: #ff0000;"></div>
</body>
</html>
<script type="text/javascript">
td_obj_old = null;
function dis(b)
{
var td_obj; td_obj = document.getElementById(b);

if (td_obj_old != null  && td_obj_old != td_obj)
{
  td_obj_old.style.display = "none";
}

td_obj_old = td_obj;

if (td_obj.style.display == "none")
{

td_obj.style.display = "block";
}
else
{
td_obj.style.display = "none";
}

}
</script>代码附上!
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312" />
<title>bbs</title>
<style type="text/css">

</style>
</head>
<body>
<script language=javascript>
function secBoard(n)
{
for(i=0;i<menu.childNodes.length;i++)
menu.childNodes[i].className="sec1";
menu.childNodes[n].className="sec2";
for(i=0;i<main.childNodes.length;i++)
main.childNodes[i].style.display="none";
main.childNodes[n].style.display="block";
}
</script>
<div id="header">
<ul id="menu">
<li onMouseOver="secBoard(0)" class="sec2">技术篇</li>
<li onMouseOver="secBoard(1)" class="sec1">生活篇</li>
<li onMouseOver="secBoard(2)" class="sec1">个人资料</li>
<li onMouseOver="secBoard(3)" class="sec1">斑竹管理</li>
</ul>

<ul id="main">
<li class="block">如何靠到最左边？</li>
<li class="unblock">如何靠到最左边2222222222容</li>
<li class="unblock">第三个内容</li>
<li class="unblock">第四个内容</li>
</ul>

</div>
</body>
</html> 请问一下这段如何把内容靠到最左边？？