<button class="btn btn-default" type="button">button标签按钮</button> 

<input type="submit" class="btn btn-default" value="input标签按钮"/>

<a href = "##" class="btn btn-default">a标签按钮</a>

<span class="btn btn-default">span标签按钮</span>  

<div class="btn btn-default">div标签按钮</div>