怎么浏览器一直报错？？、

Question

<script type="text/javascript"> window.onload = function() { var oDiv = document.getElementById('o'); oDiv.onmouseover = function() { startMove(); } } function startMove(){ var oDiv = document.getElementById('0'); setInterval(function() { oDiv.style.left = oDiv.offsetLeft+10+'px'; }, 30) }