Getting Element by Id is not working for log in system

Questions
1

html:



      <div class="login-screen">
<div class="view">
  <div class="page">
    <div class="page-content login-screen-content">
      <div class="login-screen-title">Log In</div>
      <form>
        <div class="list">
          <ul>
            <li class="item-content item-input">
              <div class="item-inner">
                <div class="item-title item-label">Username</div>
                <div class="item-input-wrap">
                  <input type="text" name="username" id="username" placeholder="Your username" />
                </div>
              </div>
            </li>
            <li class="item-content item-input">
              <div class="item-inner">
                <div class="item-title item-label">Password</div>
                <div class="item-input-wrap">
                  <input type="password" id="password" name="password" placeholder="Your password" />
                </div>
              </div>
            </li>
          </ul>
        </div>
        <div class="list">
          <ul>
            <li><a class="list-button" href="#" @click="alertLoginData">Log In</a></li>
          </ul>
          <div class="block-footer">
            <p>Please Log In</p>
            <p><a class="link login-screen-close" href="#">Close Login Screen</a></p>
          </div>
        </div>
      </form>
    </div>
  </div>
</div>

Error:
Error

Javascript:

*
2
3 
// getElementbyId
=> getElementById
4

thanks! totally didn’t see that!