<script type="text/javascript">
function sendForm(ziel) {
if(ziel == "buttonA") {
document.mainForm.action = "http://www.zielA.de/data";
document.mainForm.submit();
}
else if(ziel == "buttonB") {
document.mainForm.action = "http://www.zielB.de/data";
document.mainForm.submit();
}
}
</script>
<form action="" method="POST" name="mainForm">
<input type="button" id="buttonA" value="Ziel A" onClick="sendForm(this.id)" />
<input type="button" id="buttonB" value="Ziel B" onClick="sendForm(this.id)" />
</form>