等比例缩放
<script language="javascript" type="text/javascript">
<!--
function ImgAuto(i,MaxW,MaxH){var o=new Image();o.src=i.src;var w=o.width;var h=o.height;var t;if (w>MaxW){t=MaxW;}else{t=w;}if ((h*t/w)>MaxH){i.height=MaxH;i.width=MaxH/h*w;}else{i.width=t;i.height=t/w*h;}}
-->
</script>
onload="ImgAuto(this,150,150);"