SOURCE

你的代码
<form action="/example/html/form_action.asp" method="get">
  <p>
    Email:
    <input type="text" name="email" />
  </p>
  <p>
    Pin:
    <input type="text" name="pin" maxlength="25" style="width:400" />
  </p>
  <input type="submit" value="Submit" />
</form>
<br>
<br>
正确控制长度
<form action="/example/html/form_action.asp" method="get">
  <p>
    Email:
    <input type="text" name="email" />
  </p>
  <p>
    Pin:
    <input type="text" name="pin" maxlength="25" style="width:400px" />
  </p>
  <input type="submit" value="Submit" />
</form>