Slava-web,
и чего неработает?
<!DOCTYPE HTML>
<html>
<head>
<title>Untitled</title>
<meta charset="utf-8">
</head>
<body>
<form action="http://" onsubmit="this.username.value = this.formname.value;return false">
<input type="text" name="username" value="" />
<input type="radio" name="formname" value="значение" />
<input name="" type="submit" value="ok">
</form>
</body>
</html>