这段代码啥意思？？高手帮忙

<script language="JavaScript" type="text/JavaScript">
var pic_index=1;
var max_index=3;
var inter=null;
inter=setInterval(next,5000);
function changeall() {
for (i=1;i<4;i++) {
eval("tb"+i).style.display="none";
eval("font"+i).style.display="none";
eval("bt"+i).src="{$InstallDir}Skin/sealove/news_bt"+i+"1.gif";
}
}
function change(a) {
changeall();
pic_index=a;
eval("tb"+a).style.display="";
eval("font"+a).style.display="";
eval("bt"+a).src="{$InstallDir}Skin/sealove/news_bt"+a+"2.gif";
}
function next(){
pic_index++;
changeall();
if(pic_index>max_index){pic_index=1}
eval("tb"+pic_index).style.display="";
eval("font"+pic_index).style.display="";
eval("bt"+pic_index).src="{$InstallDir}Skin/sealove/news_bt"+pic_index+"2.gif";
}
function prev(){
pic_index--;
changeall();
if(pic_index<1){pic_index=max_index}
eval("tb"+pic_index).style.display="";
eval("font"+pic_index).style.display="";
eval("bt"+pic_index).src="{$InstallDir}Skin/sealove/news_bt"+pic_index+"2.gif";
}
</script>
<script>
function writeNewsImage(url, img) {
var str = '<a href='+url;
if (-1 < url.indexOf("(") || -1 < url.indexOf("javascript:") )
str+=' target=_self>';
else
str+=' target=_blank>';
str+='<img src='+img+' width=417 height=99 border=0 onmouseout="inter=setInterval(next,2500)" onmouseover="clearInterval(inter)" /></a>';
document.write(str);
}
function writeNewsTitle(url, des) {
var str = '<a href='+url;
if (-1 < url.indexOf("(") || -1 < url.indexOf("javascript:") )
str+=' target=_self ';
else
str+=' target=_blank ';
str += ' class=news0601 onmouseout="javascript:inter=setInterval(next,2500)" onmouseover="clearInterval(inter)" >';
str += des;
str += '</a>';
document.write(str);
}
</script>
<table height=21 cellSpacing=0 cellPadding=0 width="100%" background={$InstallDir}Skin/sealove/news_topbg.gif border=0>
<tr>
<td width=17><IMG src="{$InstallDir}Skin/sealove/space.gif"></td>
<td width=101><IMG id=bt1 onmouseover=javascript:clearInterval(inter);change(1) onmouseout=javascript:inter=setInterval(next,2500); height=21 src="{$InstallDir}Skin/sealove/news_bt12.gif" width=95 border=0 name=bt1></td>
<td width=101><IMG id=bt2 onmouseover=javascript:clearInterval(inter);change(2) onmouseout=javascript:inter=setInterval(next,2500); height=21 src="{$InstallDir}Skin/sealove/news_bt21.gif" width=95 border=0 name=bt2></td>
<td width=205><IMG id=bt3 onmouseover=javascript:clearInterval(inter);change(3) onmouseout=javascript:inter=setInterval(next,2500); height=21 src="{$InstallDir}Skin/sealove/news_bt31.gif" width=95 border=0 name=bt3></td>
<td align=right><A href="{$InstallDir}Article/Shownew.asp"><IMG {$InstallDir}Skin/sealove/More03.gif" border=0></A></td>
</tr>
</table>
<table cellSpacing=0 cellPadding=0 width="100%" border=0>
<tr>
<td width=1 bgColor=#dddcd9><IMG height=1 src="{$InstallDir}Skin/sealove/space.gif" width=1></td>
<td onmouseover=javascript:clearInterval(inter); align=middle height=185>
<table id=tb1 cellSpacing=0 cellPadding=1 width="100%" border=0>
<tr>
<td vAlign=top>
<!--{$GetArticleList(1,86,true,0,0,10,false,false,"",0,3,2,27,0,false,2,false,false,3,false,false,false,true,true,false,0,1,,,,)}--> </td>
<td vAlign=top align=middle width=150>
<!--{$GetPicArticle(1,86,True,0,1,false,false,0,3,1,130,90,19,27,True,1)}--></td>
</tr>
</table>
<table id=tb2 cellSpacing=0 cellPadding=1 width="100%" border=0>
<tr>
<td vAlign=top>
<!--{$GetArticleList(1,88,True,0,True,10,True,False,"",0,3,2,27,0,False,2,True,False,3,False,False,False,True,True,False,0,1,,,,)}--></td>
<td align=middle width=150>
<!--{$GetPicArticle(1,88,True,0,2,True,false,0,3,1,130,90,19,0,True,1)}--></td>
</tr>
</table>
<table id=tb3 cellSpacing=0 cellPadding=1 width="100%" border=0>
<tr>
<td vAlign=top>
<!--{$GetArticleList(1,87,True,0,True,10,False,True,"",0,3,2,27,0,False,2,True,False,3,False,False,False,True,True,False,0,1,,,,)}--></td>
<td align=middle width=150>
<!--{$GetPicArticle(1,87,True,0,2,false,True,0,3,1,130,90,19,0,True,1)}--></td>
</tr>
</table>
</td>
<td width=1 bgColor=#dddcd9><IMG src="{$InstallDir}Skin/sealove/space.gif"></td>
</tr>
</table>
<table cellSpacing=1 cellPadding=0 width="100%" bgColor=#dddcd9 border=0>
<tr>
<td bgColor=#f6f5f3 height=28>
<table cellSpacing=0 cellPadding=0 width="100%" align=center border=0>
<tr>
<td onmouseover=javascript:clearInterval(inter); width="80%">
<table id=font1 cellSpacing=0 cellPadding=1 width="97%" align=center border=0>
<tr>
<td width="9%"><IMG src="{$InstallDir}Skin/sealove/news_go.gif"></td>
<td width="91%"><A href="{$InstallDir}Article/Shownew.asp">最新文章更新</A></td>
</tr>
</table>
<table id=font2 cellSpacing=0 cellPadding=1 width="97%" align=center border=0>
<tr>
<td width="9%"><IMG src="{$InstallDir}Skin/sealove/news_go.gif"></td>
<td width="91%"><A href="{$InstallDir}Article/ShowHot.asp">前十篇热门文章</A></td>
</tr>
</table>
<table id=font3 cellSpacing=0 cellPadding=1 width="97%" align=center border=0>
<tr>
<td width="9%"><IMG src="{$InstallDir}Skin/sealove/news_go.gif"></td>
<td width="91%"><A href="{$InstallDir}Article/ShowElite.asp">前十篇推荐文章</A></td>
</tr>
</table>
</td>
<td align=middle width="20%">
<table cellSpacing=0 cellPadding=0 border=0>
<tr>
<td><IMG onclick=javascript:clearInterval(inter);prev(); height=22 src="{$InstallDir}Skin/sealove/news_dwonbt_r1_c1.gif" width=23></td>
<td><IMG onclick=javascript:clearInterval(inter); height=22 src="{$InstallDir}Skin/sealove/news_dwonbt_r1_c2.gif" width=24></td>
<td><IMG onclick=javascript:clearInterval(inter);next(); height=22 src="{$InstallDir}Skin/sealove/news_dwonbt_r1_c3.gif" width=24></td>
</tr>
</table>
</td>
</tr>
</table>
</td>
</tr>
</table>

这段代码就是滑动门的代码，就是标签切换。不用跳转页面，利用JS来实现不同页面在同一页面的切换显示。

如果想给图片加边框的话可以在<head></head>之间插入如下代码：

<style>
.img_brd{
border:4px solid #333;
}
</style>

然后在图片的代码上引用，比如<img src="图片地址" class="img_brd">，这样的话图片就有边框了。

border属性里边 4px是边框的粗细，solid是实线，#333是颜色。

延展内容你自己参阅相关文件吧。