how to access object in asp.net

I have a scenario... I made a class RequestAndResponse in asp.net In App_Code folder. I want to access this in Default.aspx page but i am getting a problem Here is the code:

public partial class _Default : Page
{

   RequestAndResponse request = new RequestAndResponse();

    protected void Button1_Click(object sender, EventArgs e)
    {
        try
        {

                if (!String.IsNullOrEmpty(txtbox_query.Text.Trim()))
                {

                      request.getParameter(txtbox_query.Text.Trim(), sourcePath,parameterValue);
                      request.BeginInvokeService(InvokeCompleted);

                    Response.Write(returnFromService);

                }
                else
                {
                    //to do
                }

        }
        catch (Exception error)
        {
            Response.Write(error.StackTrace);
        }

    }

    public static void InvokeCompleted(IAsyncResult result)
    {
        returnFromService = request.EndInvokeService(result);
    }

Now the scenario i hv created a object 'request' and want to access in InvokeCompleted method but i want able to do it. How will i do this??

Error: An object reference is required for the non-static field,method or property 'Default.request'