alt 属性可设置或返回浏览器不支持 checkbox 时显示的替代文本。
checkboxObject.alt=alternate_text
下面的例子返回了 checkbox 的替代文本:
<html> <body> <form> I have a bike: <input id="bike" alt="bike" type="checkbox" name="Bike" /> <br /> I have a car: <input id="car" alt="car" type="checkbox" name="Car" /> </form> <p>The alt text for the checkboxes are: <script type="text/javascript"> document.write(document.getElementById('bike').alt
); document.write(" and "); document.write(document.getElementById('car').alt
); </script></p> </body> </html>