code question: what is it?

I'm a novice at this and would be forever grateful if someone would tell
me what this code accomplishes. It is repeated 149 times on the page.
This is the 97th: (I've removed some trivial code.)

<script>
function swapon97()
{
document.img97.src="img/navigr97.gif";
}
function swapoff97()
{
document.img97.src="img/navig97.gif";
}
</script>

<a href="page97.html" onclick="return true">

<img src="navig97.gif" /></a>

then <scriptand repeat above with "98"


Thanks for any instruction or source,

Mason C

Mason C says...It's a bit of javascript which will when triggered (probably by another
bit of javascript) switch the source of each of a number (149?) of images
on the page from one value - img/navigr97.gif ('r' for red?)- to another -
img/navig97.gif (note no 'r' in the name).

From your description it's a shitty bit of coding.

Geoff M