[bes]

на js

<img src="http://javascript.ru/forum/image.php?u=19820&dateline=1334914235">
<img src="http://javascript.ru/forum/images/ca_serenity/misc/logo.gif">

<script>
window.onload = function () {
  var img = document.getElementsByTagName('img');
  var int;
  img[1].style.position = 'absolute';
  img[1].style.left = 100 + 'px';

  function goRight() {
    if (parseInt(img[1].style.left) < 120) {
      img[1].style.left = parseInt(img[1].style.left) + 1 + 'px'
    } else {
      clearInterval(int);
    }
  }

  function goLeft() {
    if (parseInt(img[1].style.left) > 100) {
      img[1].style.left = parseInt(img[1].style.left) - 1 + 'px'
    } else {
      clearInterval(int);
    }
  }

  img[0].onmouseover = function () {
    clearInterval(int);
    int = setInterval (goRight, 30);
  }

  img[0].onmouseout = function () {
    clearInterval(int);
    int = setInterval (goLeft, 30);
  }

}

</script>