ASP.NET web application on IIS

         I have created an virtual directory on IIS 5.1 for an ASP.NET 3.5 web application. The Path for the application is Http://localhost/MyApp/MyFirstPage.aspx

and when i redirect to any page in that application it shows 404 page not found error and the path have no application name "MyApp" (Ex:  Http://localhost/MyFirstPage.aspx)

Can you help..

Thanks,