MathLinkException C# - Mathematica

Question

Please help me to resolve below issue.

I am getting Mathlink Exception, while calling Wolfram Mathematica from Visual Studio2012 using C#. Please see code below. It also shows "Error code: 1012. protocol unavailable"

    private void button1_Click(object sender, EventArgs e)
    {

        // This launches the Mathematica kernel:
        IKernelLink ml = MathLinkFactory.CreateKernelLink();

        ml.WaitAndDiscardAnswer();

        // Now compute 2+2 

        string result = ml.EvaluateToOutputForm("2+2", 0);
        Console.WriteLine("2 + 2 = " + result);

        ml.Close();

        // Wait for user to close window.
        Console.WriteLine("Press Return to exit...");
        Console.Read();

    }

Exception screenshot