<script type = "text/javascript" language = "javascript">
function clear1() {
if(confirm("確定要清空數據嗎？")) {
document.main.text1.value = ""; }
}
</script>
<body>
<form name="main">
<input type="text" name="text1" />
<input type="button" name="Submit" value="清空數據" onClick="return clear1();">
</form>
</body>