div框中文字过多省略号显示css方法

<style type="text/css">
.div {width:100px;height:50px;background:#ebebeb;;text-align:center;font-family:"Microsoft YaHei";line-height:50px;color:#333;font-size:18px;position:relative;top:-1px;filter:alpha(opacity=50);
     -moz-opacity:0.7;
     -khtml-opacity: 0.7;
     opacity: 0.7;
     overflow:hidden;  
    text-overflow:ellipsis;  
    white-space:nowrap; }
</style>


<div class="div"></div>