<script>
function show()
{
alert("左上:"+parseInt(bb.style.left)+"  "+parseInt(bb.style.top)+"\n右下:"+(parseInt(bb.style.left)+bb.width)+'  '+(parseInt(bb.style.top)+bb.height))}
</script>
<body>
<IMG id="bb" src="http://blog.csdn.net/images/xml.gif"  border=0  onclick="show()" style="LEFT: 100px; TOP: 100px;POSITION: absolute;">
</body>