Webmaster Forum / HTML, CSS, Scripts / CSS / July 2008

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 <script> and repeat above with "98"

  Thanks for any instruction or source,

      Mason C