Where should I put toast statement in the try statement after finish()?

Question

I am facing error when doing toast statement in a try statement. Here is my code. Currently put a toast statement in this way (commented format). May I know what is the correct way of putting? Thanks.

try {
    httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs2));
    HttpResponse response = httpclient.execute(httppost);
    ResponseHandler<String> responseHandler = new BasicResponseHandler();
    final String response1 = httpclient.execute(httppost, responseHandler);
    System.out.println("Response : " + response1); 
    if(response1.contains("Duplicated")){
        finish();
    }
    //{Toast.makeText(getBaseContext(), "You have registered this event before.", Toast.LENGTH_LONG).show();}
    {
        jsonResult = inputStreamToString(
        response.getEntity().getContent()).toString();
    }

    catch (ClientProtocolException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    }
    return null;
}

Answer 1

Thanks for the help guys. I have fixed it myself.

    try {
        httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs2));
        HttpResponse response = httpclient.execute(httppost);
        ResponseHandler<String> responseHandler = new BasicResponseHandler();
        final String response1 = httpclient.execute(httppost, responseHandler);
        System.out.println("Response : " + response1); 
        if(response1.contains("Duplicated")){

            Register.this.runOnUiThread(new Runnable() {

                public void run() {
                    Toast.makeText(Register.this, "You have registered this event before.", Toast.LENGTH_LONG).show();

                }
            });

            finish();
        }
        jsonResult = inputStreamToString(
        response.getEntity().getContent()).toString();
    }

    catch (ClientProtocolException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    }

    return null;
}