我需要练习HTML测试的HTML和Javascript指南

Dear <span id="salutation">Name</span>;

<p>

  It has come to our attention that your invoice <span id="invoice">ID</span>

  has yet to be paid. It has now been <span id="time">some time</span> since

  you received <span id="item">the material</span> from Evil Incorporated. Please

  remit payment immediately. <span id="threaten"></span>

</p>

  Yours sincerely,<br>

<br>

<br>

  J. Smith, Accounting

<div id="buttons">
Dear <span id="salutation">Name</span>;

<p>