bootstrap下拉框式标签页

<ul id="myTab" class="nav nav-tabs">
<li class="active">
<a href="#home" data-toggle="tab">
菜鸟教程
</a>
</li>

<li class="dropdown">
<a href="#" id="myTabDrop1" class="dropdown-toggle"
data-toggle="dropdown">Java
<b class="caret"></b>
</a>
<ul class="dropdown-menu" role="menu" aria-labelledby="myTabDrop1">
<li><a href="#jmeter" tabindex="-1" data-toggle="tab">jmeter</a></li>
<li><a href="#ejb" tabindex="-1" data-toggle="tab">ejb</a></li>
</ul>
</li>
</ul>

其中<b class="caret"></b>