C#

public interface IFoo
{
    void MyMethod(); // Interface defines one method.
}

public class FooA : IFoo
{
    public void MyMethod() { Console.WriteLine("Hello from FooA"); }
}

public class FooB : IFoo
{
    public void MyMethod() { Console.WriteLine("Hello from FooB"); }
}

class Program
{
    static void Main()
    {
        Console.WriteLine("Press 1 for FooA, press 2 for FooB:");
        ConsoleKeyInfo key = Console.ReadKey(true);            
        IFoo myFoo = null;            

        if (key.KeyChar == '1')            
        {                
            myFoo = new FooA();            
        }            
        else if (key.KeyChar == '2')            
        {                
            myFoo = new FooB();            
        }
        else
        {
            throw new InvalidOperationException("Wrong selection, you must select 1 or 2"); // Always have a watch dog.
        }

        myFoo.MyMethod(); // This prints which foo was created.
    }
}

class Program
    {
        static void Main(string[] args)
        {
            Console.WriteLine((new Bar<FooA>()).ToString());
            Console.WriteLine((new Bar<FooB>()).ToString());
        }
    }

    public abstract class BaseFoo
    {
    }

    public class FooA: BaseFoo
    {
        public FooA()
        {
        }
        public override string ToString()
        {
            return "FooA";
        }
    }

    public class FooB: BaseFoo
    {
        public FooB()
        {
        }
        public override string ToString()
        {
            return "FooB";
        }
    }

    public class Bar<TFoo> where TFoo : BaseFoo, new()
    {
        TFoo tFoo = new TFoo();
        public override string ToString()
        {
            return tFoo.ToString();
        }
    }

kibromg wrote:

Thank for your response.Let me explain it a bit further

kibromg wrote:

I do not want to refresh my page i.e. every 5 seconds, i just want to refresh it ONLY on server change just like desktop applications do.

<br />
<br />
// this should select all<br />
this.txtName.SelectAll();<br />
// this should set the caret to pos 0<br />
this.txtName.SelectionStart = 0;<br />
// and this should scroll:<br />
this.txtName.ScrollToCaret();<br />