调用拨打电话组件

<nav class="mui-bar mui-bar-tab">
<a class="mui-tab-item mui-active" href="#tabbar">
<span class="mui-icon mui-icon-person"></span>
<span class="mui-tab-label">通讯录</span>
</a>
<a class="mui-tab-item" href="#tabbar-with-chat">
<span class="mui-icon mui-icon-search"></span>
<span class="mui-tab-label">查询</span>
</a>
<a class="mui-tab-item" href="tel:10086">
<span class="mui-icon mui-icon-phone"></span>
<span class="mui-tab-label">拨号</span>
</a>
<a class="mui-tab-item" href="#tabbar-with-map">
<span class="mui-icon mui-icon-more"></span>
<span class="mui-tab-label">更多</span>
</a>
</nav>
拨打电话时，未调用组件。删除 class="mui-tab-item"即可调用组件。
小弟才开始学习，准备写个通讯录。各位大神这是什么原因呀！