<!DOCTYPE html>
<html style="position: fixed;">
<head>
<meta charset="UTF-8">
<script>
function boom()
{
var cp = document.caretPositionFromPoint(0, 1);
document.documentElement.removeChild(document.body);
cp.getClientRect();
}
</script>
</head>
<body style="margin: 0;" onload="boom();"></body>
</html>