<script language="javascript">
<!--
function ChangeFontSize(size)
{
    document.getElementById('zoom').style.fontSize=size+'px';
}
-->
</script>

<a style="CURSOR:hand" onclick=ChangeFontSize(28)>大</a>
<a style="CURSOR:hand" onclick=ChangeFontSize(20)>中</a>
<a style="CURSOR:hand" onclick=ChangeFontSize(12)>小</a>

<font id=zoom>显示字体的内容</font>