怎样实现网页两侧每侧都有多个浮动广告

左栏浮动广告
<script language=javascript>var specialcode="<DIV id=searchspe style='Z-INDEX: <script language=javascript>var specialcode="<DIV id=searchspe style='Z-INDEX: 100; right: 1px; POSITION: absolute; TOP: 180px;'><TABLE cellSpacing=0 cellPadding=0 width=150 style='border-left:1px solid #2E6287;border-top:1px solid #2E6287;border-right:1px solid #2E6287;font-size:12px;color:#ffffff; border-bottom-color:#2E6287; border-bottom-width:1px'><TR bgcolor=#2E6287><TD height=20> 推荐↓</TD><TD style='CURSOR: hand' onclick=searchspe.style.visibility='hidden' width=30>关 闭</TD></TR></TABLE><table border='1' width='150' height='500' bordercolor='#2E6287'><tr><td>广告内容</td></tr></table></DIV>";document.write(specialcode);lastScrollY=0;function heartBeat0(){diffY=document.body.scrollTop;percent=.1*(diffY