<html>
<head>
<script>
function startEQ()
{
richter=5
parent.moveBy(0,richter)
parent.moveBy(0,-richter)
parent.moveBy(richter,0)
parent.moveBy(-richter,0)
timer=setTimeout("startEQ()",10)
}
function stopEQ()
{
clearTimeout(timer)
}
</script>
</head>
<body>
<form>
<input type="button" onclick="startEQ()" value="开始地震">
<br />
<br />
<input type="button" onclick="stopEQ()" value="停止地震">
</form>
</body>
</html>