Hi,
warum sollte das nicht gehen?
<html>
<head>
<script language="javascript1.2" type="text/javascript">
function go() {
document.myform.myhidden.value = "neuvalue";
document.myform.submit();
}
</script>
</head>
<body>
<form action="test.php" method="get" name="myform">
<input name="myhidden" type="hidden" value="test">
<input name="mytext" type="text" value="test">
<input type="submit" value="go">
</form>
<br><br>
<a href="#" onclick="go();return false">go</a>
</body>
</html>
Gruesse Joachim