Ad Rotation Script On Blogger

I am trying to get two ad banners to rotate on my blog but I just can not seem to get them to rotate at all.
<script LANGUAGE='Javascript'>
<!-- Beginning of Javascript -
if (document.images) {
ads = new Array(3);
ads[0] = "image location correct";
ads[1] = "image location correct";
}newplace = new Array(3);
newplace[0] = "link correct"
newplace[1] = "link correct"
var timer = null
var counter = 0
function banner() {
timer=setTimeout("banner()", 4000);
counter++;
if (counter >= 3)
counter = 0;
document.bannerad.src = ads[counter];
} function gothere() {
counter2 = counter;
window.location.href = newplace[counter2];
}
- End of Javascript - -->
</SCRIPT>

Then this is in the body
<center><a href='java script:void gothere()'>
<IMG BORDER='0' HEIGHT='60' NAME='bannerad' SRC='[URL]' WIDTH='468'/></a></center>

Now it displays the second image in the array but it will not rotate through the images. Also I enter in the code like this
<center><a href='java script:void gothere()'>
<IMG SRC='[URL]' BORDER='0' HEIGHT='60' NAME='bannerad' WIDTH='468'/></a></center>
But it displays like the one above after I have saved it.