Admob interstital not showing using google play services

hello friends,
I am using a webview in a single activity in my application, i want to show admob interstitial ads in my app.but it is not showing , and i have followed all the instruction from google support correctly. pls have a look and help.

here is my code

package com.awlabs.proverbsidiomsquotes;

import com.awlabs.proverbsidiomsquotes.R;


import android.os.Bundle;
import android.view.KeyEvent;
import android.view.Menu;
import android.webkit.WebView;

public class MainActivity extends Activity {
	private InterstitialAd interstitial;

	private WebView wv;
	private StartAppAd startAppAd = new StartAppAd(this);
	protected void onCreate(Bundle savedInstanceState) {
		StartAppAd.init(this, "10xxxx142", "20xxxx438");
		startAppAd.showAd(); // show the ad
		startAppAd.loadAd(); // load the next ad
		wv = (WebView) findViewById(;

	    // Create the interstitial.
	    interstitial = new InterstitialAd(this);
	    interstitial.setAdUnitId(" ca-app-pub-3927xxxxxxxxxxxx8/6835608784");    //new admob

	    // Create ad request.
	    AdRequest adRequest = new AdRequest.Builder().build();

	    // Begin loading your interstitial.
	public void displayInterstitial() {
        if (interstitial.isLoaded()) {
	public boolean onKeyDown(int keyCode, KeyEvent event) {
	    // Check if the key event was the Back button and if there's history
	    if ((keyCode == KeyEvent.KEYCODE_BACK) && wv.canGoBack()) {
	    return super.onKeyDown(keyCode, event);


the app is running and starapp banners are being shown, but no interstitial ads of admob.

Well, here the things looks fine to me everything is placed over the appropriated place, that’s just a bit more weird do one thing try copy and pasting the code again and wait for a bit more longer this time. If that still doesn’t helps you out I would say try calling the admob and look for support.

Try to use code again and wait for some to see ad. Do not use another ad platform to show ad on the same screen which you are trying to show admob ads.