css模態框

<!-- 註冊窗口 --><div id="register" class="modal fade" tabindex="-1">   <div class="modal-dialog">      <div class="modal-content">         <div class="modal-body">            <button class="close" data-dismiss="modal">               <span>&times;</span>            </button>         </div>         <div class="modal-title">            <h1 class="text-center">註冊</h1>         </div>         <div class="modal-body">            <form class="form-group" action="">               <div class="form-group">                  <label for="">用戶名</label>                  <input class="form-control" type="text" placeholder="6-15位字母或數字">               </div>               <div class="form-group">                  <label for="">密碼</label>                  <input class="form-control" type="password" placeholder="至少6位字母或數字">               </div>               <div class="form-group">                  <label for="">再次輸入密碼</label>                  <input class="form-control" type="password" placeholder="至少6位字母或數字">               </div>               <div class="form-group">                  <label for="">郵箱</label>                  <input class="form-control" type="email" placeholder="例如:123@123.com">               </div>               <div class="text-right">                  <button class="btn btn-primary" type="submit">提交</button>                  <button class="btn btn-danger" data-dismiss="modal">取消</button>               </div>               <a href="" data-toggle="modal" data-dismiss="modal" data-target="#login">已有帳號？點我登陸</a>            </form>         </div>      </div>   </div></div><!-- 登陸窗口 --><div id="login" class="modal fade">   <div class="modal-dialog">      <div class="modal-content">         <div class="modal-body">            <button class="close" data-dismiss="modal">               <span>&times;</span>            </button>         </div>         <div class="modal-title">            <h1 class="text-center">登陸</h1>         </div>         <div class="modal-body">            <form class="form-group" action="">               <div class="form-group">                  <label for="">用戶名</label>                  <input class="form-control" type="text" placeholder="">               </div>               <div class="form-group">                  <label for="">密碼</label>                  <input class="form-control" type="password" placeholder="">               </div>               <div class="text-right">                  <button class="btn btn-primary" type="submit">登陸</button>                  <button class="btn btn-danger" data-dismiss="modal">取消</button>               </div>               <a href="" data-toggle="modal" data-dismiss="modal" data-target="#register">尚未帳號？點我註冊</a>            </form>         </div>      </div>   </div></div>