Here's the test page I'm using. This version works fine, forwarding to #success:
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html><head>
<script type="text/javascript" src="prototype.js"></script>
</head><body>
<form id='form' method='POST' action='#fail'>
<button id='button'>Oh my giddy aunt!</button>
<script type="text/javascript">
var fn = function() {
$('form').action = "#success";
$('form').submit();
}
$('button').observe('mousedown', fn);
</script>
</form>
</body></html>
If I empty the handler:
var fn = function() {
}
The form is submitted, but of course we are sent to #fail this time.
With an alert in the handler:
var fn = function() {
alert("omg!");
}
The form is not submitted. This is awfully curious.
With event.stop(), which is supposed to prevent the browser taking the default action:
var fn = function(event) {
event.stop();
}
We are sent to #fail.
So alert() is more effective at preventing a submission than event.stop(). What gives?
I'm using Firefox 3.6.3 and Prototype 1.6.0.3. This behaviour also appears in Prototype 1.6.1.