změna obrázku a klikací mapa

To je vec JS, ptal bych se v JS.
Ty mapy mas silene velike, nemusis presne kopirovat okraje obrazku, mi to vyslo asi na 11-15 puntiku.

Osobne bych to asi resil tak, ze bych prepisoval obrazek a celou mapu v divu pomoci innerHTML, ale urco by melo jit menit coords

<div id="obr1">
<img src="aaa.gif" ...>
<map ... onclick=zmen(1,4)>
</div>

<script>
pole=[
"aaa",",30,103","157,89,30,103","1,2,3,4"
"bbb",",30,103","157,89,30,103","1,2,3,4"
"ccc",",30,103","157,89,30,103","1,2,3,4"
"ddd",",30,103","157,89,30,103","1,2,3,4"
]

function zmen(co,naco)
{var a,b,t;t='';
a=naco*3;
t+='<img src="'+pole[a]+'.gif">';
t+='<map>'
t+='<area coords="'+pole[a+1]+'">'
t+='<area coords="'+pole[a+2]+'">'
t+='<area coords="'+pole[a+3]+'">'
t+='</map>'
obji("obr"+co,t);
}

function objGet(x)
{return document.getElementByID(x)}
function objv(x,z)
{objGet(x).innerHTM=z}
</script>

Jinak ti nezhasina menu ve Firefoxu (IE radeji nepoustim)
graficky je to zajimave, kolem obrazku dole bych dal ramecek, kolem framu s temi obrazky bych dal take ramecek. Je to takove divne, kdyz se zobrazi scroll uprostred stranky a oblast neni oramovana nebo jinak vydelena