求解高手解答下，谢谢
<!Doctype html>
<html>
<head>
<title>无标题文档</title>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
</head>
<body>
<form action="save.php" method="post">
<label for="myName">姓名</label>
<input type="text" value="" name="myName" />
<input type="submit" value="提交" name="submitBtn" />
</form>
</body>
</html>
name="submitBtn" 我想知道submitBtn这个从哪来的
