I would like to know how to display a Admob interstitial ad every time a button is pressed. I have managed to display a interstitial ad, but only on the first time the button is pressed. Here is my code: 

```
package com.mycash.borgjake.mycash;

import android.content.Intent;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;

import android.widget.Button;
import android.widget.TextView;

import android.view.View;

import com.google.android.gms.ads.AdListener;
import com.google.android.gms.ads.AdRequest;
import com.google.android.gms.ads.AdView;
import com.google.android.gms.ads.InterstitialAd;

import static com.mycash.borgjake.mycash.R.styleable.View;

public class MainActivity extends AppCompatActivity {

private InterstitialAd mInterstitial;

Button btnClick;
Button btnWithdraw;

TextView txtBalance;

@Override
protected void onCreate(Bundle savedInstanceState) {

    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    AdView adView = (AdView)findViewById(R.id.adView);
    AdRequest adRequest = new AdRequest.Builder()
            .addTestDevice(AdRequest.DEVICE_ID_EMULATOR)
            .build();
    adView.loadAd(adRequest);

    btnClick = (Button) findViewById(R.id.button);

    txtBalance = (TextView) findViewById(R.id.textView);

    btnClick.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            String countValue = txtBalance.getText().toString();
            int dblCountValue = Integer.parseInt(countValue);

            if(mInterstitial.isLoaded()) {
                mInterstitial.show();
            }

            dblCountValue++;
            txtBalance.setText(String.valueOf(dblCountValue));

        }
    });

    mInterstitial = new InterstitialAd(this);
    mInterstitial.setAdUnitId("...");
    AdRequest request = new AdRequest.Builder()
            .addTestDevice(AdRequest.DEVICE_ID_EMULATOR)
            .build();
    mInterstitial.loadAd(request);

}

public void onButtonClick(View v) {
    if(v.getId() == R.id.button2) {
        Intent i = new Intent(MainActivity.this, Withdraw.class);
        startActivity(i);
    }
  }
}

```

Thanks for the help in advance :)