Untitled

<!DOCTYPE html>
<html lang="en" style="display: table; margin: auto;">
<head>
    <meta charset="UTF-8">
    <title>Task 4.1</title>
</head>
<body style="display: table-cell; vertical-align: middle;">
<label for="txtOut">Output from Task 3.3:</label>
<input type="text" id = "txtBookTitle" value="Snømannen">
<button id= "btnAddBook" onclick ="btnAddBookClick()" > Legg til bok!</button>
<div style="padding: 10px; margin: 10px; min-width: 500px; border: darkblue thin solid; background-color: antiquewhite">
    <span id="txtOut" style="white-space:nowrap;"></span>
</div>
<script>
  "use strict";
  const DOMTextOut = document.getElementById("txtOut");
  const NEWLine = "\r\n";

  function printOut(aText) {
    if (DOMTextOut.innerText.length !== 0) {
      DOMTextOut.innerText += NEWLine;
    }
    DOMTextOut.innerText += aText;
  }

  const txtBookTitle = document.getElementById("txtBookTitle");

  function btnAddBookClick(){
      if (txtBookTitle.value === "Snømannen"){
          printOut("Dette er ingen bok");
      }else{
          printOut(txtBookTitle.value);
      }
  }