<head>
<script>
function resizeRock() {
document.getElementById('rockimg').style.height =
(document.body.clientHeight - 100) * 0.9;
}
</script>
</head>
<body onload="resizeRock()">
<img id="rockimg" src="pegoet.png">
</body>function resizeRock() {
document.getElementById('rockimg').style.height =
((document.body.clientHeight - 100) * 0.9)+"px";
}
