火狐、Safari、IE
可以看到在不同的浏览器中出现 1-2 px 的差异input，div如何清除呢？
HTML：
<input type="text" class="my-input-select" disabled="disabled"/>
<div class="my-input-select-box" >
<ul style="z-index:100">
<li>All</li>
<li>Products</li>
<li>Categories</li>
<li>Clients</li>
<li>News</li>
</ul>
</div>
CSS：
.my-input-select{
border: 1px solid #acacac;
-webkit-border-radius: 5px;
-moz-border-radius: 5px;
border-radius: 5px;
padding: 5px;
background: url(images/forms/select.png) no-repeat 98% center;
cursor: pointer;
display: block;
}
div.my-input-select-box{
position: relative;
margin: 0;
padding: 0;
}
div.my-input-select-box ul{
position: absolute;
background: red;
left: 110px;
top: 26px;
width: 172px;
z-index: 100;
margin: 0;
padding: 0;
}
div.my-input-select-box li{
border-bottom: medium none;
color: #393939;
cursor: pointer;
display: block;
font-size: 12px;
line-height: 12px;
list-style-type: none;
margin: 0;
padding: 6px 2px 6px 10px;
}