7 document.getElementById("target").style.height = "100px";
12 <div style="height: 50px; background: red; width: 100px;" id="target">
13 <div style="height: 100%">
15 <iframe style="vertical-align: bottom; width: 100%; height:100%; background: green; border: 0;"></iframe>
20 document.body.offsetTop;