form-JAVA點擊按鈕 將Form窗體的hidden屬性的true值改為false?

JAVA點擊按鈕 將Form窗體的hidden屬性的true值改為false?

<

 button type="button">管理員登陸</button>
點擊管理員登陸這個按鈕，將下面的Form窗體的hidden屬性值如何變為false
<form action="${ctx}/login.action" id="loginForm" method="post" hidden="true">
                <input type="text" autocomplete="off" id="lname" name="lname" placeholder="用戶名"
                    required="required" /> <input type="password" id="pwd" name="pwd"
                    placeholder="密碼" required="required" /> <input autocomplete="off" type="text" id="cc"
                    name="cc" placeholder="驗證碼" required="required" /> 
                    <img src="${ctx}/cc.action" id="img_cc" title="點擊更換" style="cursor: pointer;"/>
                <button type="submit" onclick="ss" data-toggle="modal" data-target=".bs-example-modal-lg" class="lo">登錄</button>
                <div id="msg">${msg}</div>
                <c:remove var="msg" scope="session"/>
                </form>

最佳回答：

 <button type="button" onclick="document.getElementById('loginForm').setAttribute('hidden',false)">管理員登陸</button>