Can't display validation error message

Hi,

With Spring MVC 3.0.6, my web application can't display error message using java validation annotations.

Here is my pojo class:

book.java:

BookFormController.java file:

import ix.houseware.category.bean.Book;
import java.util.Map;
import javax.validation.Valid;
import org.springframework.stereotype.Controller;
import org.springframework.validation.BindingResult;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;

@Controller  
@RequestMapping("/book")  
public class BookFormController  
{  
    // Display the form on the get request  
    @RequestMapping(method=RequestMethod.GET)  
    public String showForm(Map model)  
    {  
        Book book  = new Book();  
        model.put("book", book);  
        return "bookForm";  
    }  
  
    // Process the form.  
    @RequestMapping(method=RequestMethod.POST)  
    public String processForm(@Valid Book book, BindingResult result, Map model)  
    {  
        // Persistence logic to save the book will go here  
        if (result.hasErrors()) {
            return "bookForm";
        }
    // Persistence logic to save the book will go here  
        // Add the saved book to the model  
        model.put("book", book);  
        return "bookResult";  
    }  
}

bookForm.jsp file:

When entered nothing in the 'name' and 'description' edit box and press the Create button, error message is not shown.

What would be the problem and missing code in my files?

Any suggestion would be very appreciated.
Thanks
Sam