// bootstrap下拉菜单
<div class="btn-group">
<button id="button_text" type="button" class="btn btn-default dropdown-toggle" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
Action <span class="caret"></span>
</button>
<ul class="dropdown-menu">
<li><a href="#" class="a-1">Action</a></li>
<li><a href="#" class="a-1">Another action</a></li>
<li><a href="#" class="a-1">Something else here</a></li>
<li role="separator" class="divider"></li>
<li><a href="#" class="a-1">Separated link</a></li>
</ul>
</div>
// click down box option, the replacement display content
$ ( ". 1-A.") The Click (function () {.
Var Val = $ (the this) .html ();
. $ ( "# BUTTON_TEXT") text (Val )
})