[Vlasenko Fedor]

<form>
  <font class="tablebodytext">
    <p>текст</p>
    <input type="submit" value="Оплатить" name="BuyButton">
  </font>
</form>
<script>
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    var allfont = document.querySelectorAll("font.tablebodytext");
    var len = allfont.length;
    var el = null;
    if (len) {
      while (len--) {
        el = allfont[len];
        el.outerHTML = el.innerHTML;
      }
    }
  }
</script>