Untitled

<!DOCTYPE html>
<html lang="en">
<head>
	<title>Login</title>
</head>
<body style="background-color:#68eff1;">

<div id="info"></div>
<script type="text/javascript">

var user=document.form1.user.value;
var pass=document.form1.password.value;

var datosJSON = '{"usuario" : "user", "contraseña" : "pass"}';

function mostrar(datos.JSON){
document.write(datos.JSON.usuario);
document.write(datos.JSON.contraseña);
};

</script>
<form name="form1">
<P>User:     <INPUT type=text name=user placeholder="User">
<P>Password: <INPUT type=text name=password placeholder="Password">
<P>
<input type="button" name="miboton" id="boton" 	value="Enviar" onClick="mostrar(datos.JSON)" />
</form>
</body>
</html>