<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>函数</title>
</head>
<body>
<script type="text/javascript">
function study(count) {
for (var i = 0; i < count; i++) {
document.write("<h4>欢迎学习JavaScript</h4>")
}
}
</script>
<input name="btn" type="button" value="请输入次欢迎学习JavaScript的次数" onclick="study(prompt('请输入显示欢迎学习JS的次数:',''))"/>
</body>
</html>