<!DOCTYPE HTML>
<style>
html, body {
    margin: 0;
    padding: 0;
}
#big {
    width: 125px;
    height: 500px;
    background: blue;
}
#small {
    position: absolute;
    top: 0;
    left: 0;
    width: 100px;
    height: 100px;
    background: green;
}
</style>
<div id='big'></div>
<div id='small'></div>
<script>
window.onload = window.parent.onFrameLoaded();
</script>