JavaScript:多图片变化且每次的效果不同

<script language=JavaScript>
var imgUrl=new Array();
var imgLink=new Array();
var adNum=0;
imgUrl[1]="http://www.smallrain.net/jsimg/1.jpg";
imgLink[1]="#1";
imgUrl[2]="http://www.smallrain.net/jsimg/2.jpg";
imgLink[2]="#2";
imgUrl[3]="http://www.smallrain.net/jsimg/3.jpg";
imgLink[3]="#3";
imgUrl[4]="http://www.smallrain.net/jsimg/4.jpg";
imgLink[4]="#4";

imgUrl[5]="http://www.smallrain.net/jsimg/2.jpg";
imgLink[5]="#2";
var imgPre=new Array();
var j=0;
for (i=1;i<=5;i++) {
if( (imgUrl[i]!="") && (imgLink[i]!="") ) {
j++;
} else {
break;
}
}

function playTran(){
if (document.all){
document.imgInit.filters[0].play();
}
}

function nextAd(){
if(adNum<j)adNum++ ;
else adNum=1;

if (document.all){
document.imgInit.filters[0].Transition=26;
document.imgInit.filters[0].apply();
}
document.images.imgInit.src=imgUrl[adNum];
playTran();
theTimer=setTimeout("nextAd()", 6000);
}

function goUrl(){
jumpUrl=imgLink[adNum];
jumpTarget='_blank';
if (jumpUrl != ''){
if (jumpTarget != '')
window.open(jumpUrl,jumpTarget);
else
location.href=jumpUrl;
}
}
</script>
<a href="#" onclick="goUrl()" target="_parent"><img style="FILTER:
progid:DXImageTransform.Microsoft.RevealTrans (duration=1,transition=3);
; border-color:#000000;color:#000000;margin-bottom:-5px" src="javascript:nextAd()" height=100 width=150 border=0 name=imgInit></a>