网页特效代码：新闻切换特效的实现

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<SCRIPT language=JavaScript type=text/javascript>
var nn;
nn=1;
setTimeout('change_img()',6000);
function change_img()
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function setFocus1(i)
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function selectLayer1(i)
{
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<DIV class=focusPic>
<DIV id=focusPic1 style="DISPLAY: none">
<DIV class=pic><A href="http://tech.163.com/special/000915SN/soft2005.html"><IMG height=180 alt=网易学院05年软件评选结果 src="http://cimg.163.com/tech/2006/1/18/2006011810122068706.jpg" width=240 border=0></A> </DIV>
<H2><A href="http://tech.163.com/special/000915SN/soft2005.html">网易学院05年软件评选结果</A></H2>
<P>经过大家的热情投票和我们的辛劳整理，网易学院2005年年度软件评选结果终于出炉啦。点击进入查看……<IMG height=5 alt=详细 src="/newimg/i2.gif" width=3> <A class=cDRed href="http://tech.163.com/special/000915SN/soft2005.html">详细</A></P></DIV>
<DIV id=focusPic2 style="DISPLAY: none">
<DIV class=pic><A href="http://tech.163.com/discover/"><IMG height=180 alt=颠覆丛林动物生存法则 src="http://cimg.163.com/tech/2006/1/17/200601171557008cee7.jpg" width=240 border=0></A> </DIV>
<H2><A href="http://tech.163.com/discover/">颠覆丛林动物生存法则</A></H2>
<P>群居动物的这种行为颠覆了我们通常认为的，在动物世界通行的 “丛林法则”，动物不都自私，不都是弱肉强食的。<IMG height=5 alt=详细 src="/newimg/i2.gif" width=3> <A class=cDRed href="http://tech.163.com/discover/">详细</A></P></DIV>
<DIV id=focusPic3 style="DISPLAY: none">
<DIV class=pic><A href="http://tech.163.com/special/00091MNJ/itobserve015.html"><IMG height=180 alt=WAPI并非贸易阴谋 src="http://cimg.163.com/tech/2006/1/17/2006011711483290a60.jpg" width=240 border=0></A> </DIV>
<H2><A href="http://tech.163.com/special/00091MNJ/itobserve015.html">WAPI并非贸易阴谋</A></H2>
<P>近日国家做出决定：“将向其他的国内及国外企业公布该算法”。事实证明中国WAPI标准并非是贸易阴谋。<IMG height=5 alt=详细 src="/newimg/i2.gif" width=3> <A class=cDRed href="http://tech.163.com/special/00091MNJ/itobserve015.html">详细</A></P></DIV>
<DIV id=focusPic4 style="DISPLAY: block">
<DIV class=pic><A href="http://tech.163.com/special/00091OSI/horizons.html"><IMG height=180 alt=新视野号探测冥王星特别专题 src="http://cimg.163.com/tech/2006/1/17/200601171002503f251.jpg" width=240 border=0></A> </DIV>
<H2><A href="http://tech.163.com/special/00091OSI/horizons.html">新视野号探测冥王星特别专题</A></H2>
<P>美国宇航局将于北京时间18日凌晨2时24分发射新视野号探测器，造访这颗人类唯一尚未探测过的行星-冥王星。<IMG height=5 alt=详细 src="/newimg/i2.gif" width=3> <A class=cDRed href="http://tech.163.com/special/00091OSI/horizons.html">详细</A></P></DIV>
<DIV class=more>
<DIV class=textNum>
<DIV class=text>&gt; 更多头图新闻</DIV>
<DIV class="num bg1" id=focusPic1nav style="DISPLAY: none">
<UL>
<LI>1 </LI>
<LI><A href="javascript:setFocus1(2);" target=_self>2</A> </LI>
<LI><A href="javascript:setFocus1(3);" target=_self>3</A> </LI>
<LI><A href="javascript:setFocus1(4);" target=_self>4</A> </LI></UL></DIV>
<DIV class="num bg2" id=focusPic2nav style="DISPLAY: none">
<UL>
<LI><A href="javascript:setFocus1(1);" target=_self>1</A> </LI>
<LI>2 </LI>
<LI><A href="javascript:setFocus1(3);" target=_self>3</A> </LI>
<LI><A href="javascript:setFocus1(4);" target=_self>4</A> </LI></UL></DIV>
<DIV class="num bg3" id=focusPic3nav style="DISPLAY: none">
<UL>
<LI><A href="javascript:setFocus1(1);" target=_self>1</A> </LI>
<LI><A href="javascript:setFocus1(2);" target=_self>2</A> </LI>
<LI>3 </LI>
<LI><A href="javascript:setFocus1(4);" target=_self>4</A> </LI></UL></DIV>
<DIV class="num bg4" id=focusPic4nav style="DISPLAY: block">
<UL>
<LI><A href="javascript:setFocus1(1);" target=_self>1</A> </LI>
<LI><A href="javascript:setFocus1(2);" target=_self>2</A> </LI>
<LI><A href="javascript:setFocus1(3);" target=_self>3</A> </LI>
<LI>4 </LI></UL></DIV></DIV></DIV></DIV>