如何得到span标签的尺寸？

Question

<span id=a>abc</span>
<input type=button value=get onclick="alert(document.getElementById('a').offsetWidth);alert(document.getElementById('a').offsetHeight)"/>

Answer 1

<span id="span1">abc</span>document.getElementById("span1").offsetWidth
document.getElementById("span1").offsetHeigth

Answer 2

关于scrollLeft,scrollWidth,clientWidth,offsetWidth属性，参考
http://my.opera.com/yuyii/blog/show.dml/284840

Answer 3

<script type="text/javascript">
function spansize(){
var sp=document.getElementsByTagName("span")[0];
var xx=sp.offsetWidth;
var yy=sp.offsetHeight;
alert("宽= "+xx+"\n高= "+yy);
}
window.onload=spansize;
</script>
<span>aasdasfbcasdfasfasf</span>