Prototype - Form.Element activate() 方法
此方法将焦点放在表单控件上，如果是文本输入，则选择其内容。
此方法只是聚焦和选择的快捷方式。因此，它们是等效的 −
Form.Element.focus('myelement').select();
相当于:
$('myelement').activate();
语法
formElement.activate();
返回值
它返回一个 HTML 元素。
示例
以下示例将激活 age 字段 −
<html>
<head>
<title>Prototype examples</title>
<script type = "text/javascript" src = "/javascript/prototype.js"></script>
<script>
function showResult() {
$('age').activate()
}
</script>
</head>
<body>
<p>单击按钮查看结果。</p>
<br />
<form id = "example" action = "#" onsubmit = "return false">
<fieldset><legend>User info</legend>
<div>
<label for = "username">Username:</label>
<input name = "username" id = "username" value = "Sai" type = "text">
</div>
<div>
<label for = "age">Age:</label>
<input name = "age" id = "age" value = "23" size="3" type="text">
</div>
<div>
<label for = "hobbies">Your hobbies :</label>
<select name = "hobbies" id = "hobbies" multiple = "multiple">
<option>coding</option>
<option>swimming</option>
<option>hiking</option>
<option>drawing</option>
</select>
</div>
</fieldset>
</form>
<br />
<input type = "button" value = "Result" onclick = "showResult();"/>
</body>
</html>
输出
prototype_form_management.html
