I need help to change the JS

I think the code will show the ad at random,but i want the ad be load one by one ,5s interval
anyone help me will be appreciated or is there have another codes to do the job?


<script language=”javascript”>
var how_many_ads = 3;
var now = new Date()
var sec = now.getSeconds()
var ad = sec % how_many_ads;
ad +=1;
if (ad==1) {
txt=”“;
url=”“;
alt=”“;
banner=”“;
width=”468″;
height=”60″;
}
if (ad==2) {
txt=” “;
url=” “;
alt=” “;
banner=” “;
width=”468″;
height=”60″;
}
if (ad==3) {
txt=” “;
url=” “;
alt=” “;
banner=” “;
width=”468″;
height=”60″;
}
document.write(’<center>’);
document.write(’<a href=”‘ + url + ‘” target=”_top”>’);
document.write(’<img src=”‘ + banner + ‘” width=’)
document.write(width + ‘ height=’ + height + ‘ ‘);
document.write(’alt=”‘ + alt + ‘” border=0><br>’);
document.write(’<small>’ + txt + ‘</small></a>’);
document.write(’</center>’);
</script>

 

Check this out, with a bit of tweaking it will do the job

http://stackoverflow.com/questions/11350993/using-jquery-loop-to-alternate-image-scr