Napr takto:
Kód:
<html>
<head>
  <title>Page</title>
  <script type="text/javascript">
    function showPic(pic)
    {
      var obj = document.getElementById('view');
      if(!obj) return;

      if(pic=='') {
        obj.innerHTML = "";
      }
      else {
        obj.innerHTML = "<img src=\""+pic+"\" alt=\""+pic+"\" />";
      }
    }
  </script>
</head>
<body>
  <div>
    <span onmouseover="showPic('obrazek1.jpg')" onmouseout="showPic('')">Obrazek1</span><br />
    <span onmouseover="showPic('obrazek2.jpg')" onmouseout="showPic('')">Obrazek2</span>
  </div>
  <div id="view" style="border: 1px solid #000000; width: 640px; height: 480px;">
  </div>
</body>
</html>
V divu "view" se zobrazuji obrazky..staci najet na jeden ze spanu nad nim. Ty muzes nahradit treba jinymy obrazky v mensim rozmeru.