使用javascript定时器定时调用一个function，不能用SetTimer，要使用setInterval
<html>
<head>
<script language="javascript">
var timerHandle;
// invoke alertalertalert every 1 seconds
timerHandle = setInterval("alertalertalert()", 1000);
function alertalertalert() {
document.getElementById("tthandle").value = document.getElementById("tthandle").value + "Hello here." + "\n";
}
function releaseTimer() {
clearInterval(timerHandle);
}
</script>
<body onunload="releaseTimer()">
<textarea cols="100" rows="10" readonly id="tthandle"></textarea>
</body>
</html>
<head>
<script language="javascript">
var timerHandle;
// invoke alertalertalert every 1 seconds
timerHandle = setInterval("alertalertalert()", 1000);
function alertalertalert() {
document.getElementById("tthandle").value = document.getElementById("tthandle").value + "Hello here." + "\n";
}
function releaseTimer() {
clearInterval(timerHandle);
}
</script>
<body onunload="releaseTimer()">
<textarea cols="100" rows="10" readonly id="tthandle"></textarea>
</body>
</html>
