查看一个图片是否加载完成：
<img id="img1" src="http://pic1.xxx.com/wall/f/51c3bb99a21ea.jpg">
<p id="p1">loading...</p>
<script type="text/javascript">
img1.onload = function() {
p1.innerHTML = 'loaded'
}
</script>
查看一个图片是否加载完成：
<img id="img1" src="http://pic1.xxx.com/wall/f/51c3bb99a21ea.jpg">
<p id="p1">loading...</p>
<script type="text/javascript">
img1.onload = function() {
p1.innerHTML = 'loaded'
}
</script>