I have problem when i read a tutorial about spring mvc.The project have jsp page like:

<html>
<head>

<title>Spring 3.0 MVC Series: Hello World - ViralPatel.net</title>
</head>
<body>
hello!
${inf}
</body>
</html>

And when i set a value for the inf in the controller,but,the "${inf}" fails to retirve the value.

what should i do now?

thx

add:
the controller's code:

package net.viralpatel.spring3.controller;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMap ping;
import org.springframework.web.portlet.ModelAndView;


@Controller
public class HelloWorldController {

@RequestMapping("hello")
public ModelAndView helloWorld() {

String message = "Hello World, Spring 3.0!";
System.out.println(message);
ModelAndView modelandview=new ModelAndView("hello");
modelandview.addObject("inf", message);
//return new ModelAndView("hello", "message", message);
return modelandview;
}

}