html手机3列自适应

<style>

#left {

width:100px; background-color:blue;

height:100px; float:left;

}

#right {

width:50px; background-color:yellow;

height:100px;

float:right;

}

#main {

background-color:red; height:100%;

}

</style>

<div style="width:100%">

<div id="left">left </div>

<div id="right">right</div>

<!--main要写到最后一个-->

<div id="main">mian</div>

</div>