设置背景图片，解决手机上背景图片高度适应问题

<img src="url" class="PhoneBack">//url为图片地址

.PhoneBack{
position: fixed;
z-index: -10;    
display: block;
width: 100%;
height: 100%;
}

标签1：
<div class="PhoneBack">
//其他内容
</div>

样式1：
.PhoneBack{
    position: fixed;
    z-index: -10;
    background: url('../Images/weixin/NowRegister/RegisterBack.png') no-repeat 0px 0px;
    width: 100%;
    height: 100%;
    /*background-repeat: no-repeat;
    background-position: 0px 0px;*/
    background-size: 100% 100%;
}