Или так...
<!DOCTYPE html>
<html>
<head>
<meta http-equiv='Content-Type' content='text/html; charset=windows-1251' />
<!--
<script src='http://code.jquery.com/jquery-latest.js'></script>
<script src="https://code.angularjs.org/1.3.9/angular.min.js"></script>
<script src="https://code.angularjs.org/1.3.9/angular-route.js"></script>
-->
<style type='text/css'>
</style>
<script type='text/javascript'>
function test(){
var o=document.getElementsByName('test0');
o[1].value=o[0].value;
document.getElementsByTagName('form')[1].submit();
return true;
};
</script>
</head>
<body>
<form>
<input type='text' name='test0' />
</form>
<form onsubmit='return test();'>
<input type='hidden' name='test0' />
<input type='text' name='test1' />
<button>Send</button>
</form>
</body>
</html>