手机屏幕图片自适应

<script>
var x = navigator;
var w=window.innerWidth || document.documentElement.clientWidth || document.body.clientWidth;
var h=window.innerHeight || document.documentElement.clientHeight || document.body.clientHeight;
//分辨率小于360

//alert(w); 

 if(w<360){
 // alert(22);
  var imgs = document.getElementById("pingguo").getElementsByTagName("img");  
 //var imgs=$("#detail_span img");
// alert(imgs.length);
for (var i=0;i<imgs.length;i++) { 
  // alert(imgs[i].src); //测试成功 
  var height=parseInt(imgs[i].height * 300 / imgs[i].width);
   imgs[i].style.height=height+"px";
   imgs[i].style.width="300px";
   
} 

}
</script>