Text replacement with URL help?

I'm trying to start an Ajax request to return "successfully entered" in the accordingly chosen show URL, but instead, somehow the show ID is showing up instead! I have no idea where this is coming from.

Script: <script type="text/javascript" src="prototype.js"></script>
<script>
function replace(show_id,dog_id) {

new Ajax.Request("ajaxentershow.php",
{
method: 'post',
postBody: 'show_id='+show_id+'&dog_id='+dog_id,
onComplete: showResponse
});
}

function showResponse(req){
$F('foo'+show_id).innerHTML= req.responseText;
}

</script>

<?php
print "<b><a href='#' onClick='replace($row[show_id],$dog_id)'><div id='foo$row[show_id]'>enter this show</div></a></b><br>";
?>


All irrelevant code has been removed so you guys can see where the problem lies. Firebug shows my 'foo' fields are showing up correctly and that the show_id and dog_id are being passed correctly, but I don't think the replace() function I made is being activated because I tried sticking an alert() in there to test it, and it wouldn't show up.

TIA.

-Alyssa

I simply changed the function name because I wondered if maybe it was a built in function, and now it says my function isn't defined, though it clearly is.

Help?