文档状态改变

<iframe src="a.html" id="f" name="f" scrolling="no" frameborder=0 marginwidth=0 marginheight=0></iframe>
<script>
var doc=window.frames["f"].document;
function s(){
if (doc.readyState=="complete"){
document.all.f.style.height=doc.body.scrollHeight
document.all.f.style.width=doc.body.scrollWidth
}
}
doc.onreadystatechange=s
</script>