You can add a property value to submit button. But you need onclick handler on the submit buttons to do it consistently. (If you use onclick handler to submit button, event.srcElement would be available in ie. I guess that's why you ask specifically for moz.)
I set "fired" boolean property.
[tt]
<html>
<head>
<script language="javascript">
function checkit(obj) {
var csubmitbtn=document.forms[obj.name].sbmt
for (var i=0; i<csubmitbtn.length;i++) {
if (csubmitbtn.fired) {
alert("submit button value submitted: " + csubmitbtn.value)
}
}
//continue with other validation to determine the return
//I use return false to stop submit for testing
return false;
}
function setfired(obj) {
var csubmitbtn=document.forms[obj.form.name].elements[obj.name];
for (var i=0; i<csubmitbtn.length;i++) {
csubmitbtn.fired=false;
}
obj.fired=true;
}
</script>
</head>
<body>
<form name="form1" onsubmit="return checkit(this)">
<input type="text" name="txt11" value="txt11" />
<input type="submit" name="sbmt" value="submit1" onclick="setfired(this)" />
<input type="submit" name="sbmt" value="submit2" onclick="setfired(this)" />
<input type="submit" name="sbmt" value="submit3" onclick="setfired(this)" />
<input type="submit" name="sbmt" value="submit4" onclick="setfired(this)" />
</form>
</body>
</html>
[/tt]
If you use script to assign submit handler, it would be something like this.
[tt]
window.document.form1.onsubmit=function() {
checkit(document.forms["form1"]);
}
[/tt]
which corresponds to your Validate.