i am getting the null pointer Exception at ViewRoot.Draw(boolean) in android.how to solve this?

here is my code


LayoutInflater li= LayoutInflater.from(this);
        		View textEntryView = li.inflate(R.layout.alertbox, null);

        		final AlertDialog.Builder dialog = new AlertDialog.Builder(this);
        	    dialog.setTitle("Enter the places");
        	    dialog.setView(textEntryView);

        	  splc = (EditText) textEntryView.findViewById(R.id.strtplace);
        	    dialog.setPositiveButton("Ok", new OnClickListener(){

					@Override
					public void onClick(DialogInterface dialog, int which) {
						// TODO Auto-generated method stub
						pd = ProgressDialog.show(TravellogActivity.this, "Working..", "Searching your address", true, false);
						//Show a progress dialog


						searchAdress = new Thread(){
						public void run(){
								String addressInput = splc.getText().toString(); // Get input text
								try {
									foundAdresses = gc.getFromLocationName(addressInput, 5); // Search addresses
									Thread.sleep(1500);
								} catch (Exception e) {
									// @todo: Show error message
								}
								showAdressResults.sendEmptyMessage(0);
							}
						};
						searchAdress.start();

					}
				});




 private Handler showAdressResults = new Handler() {
        	        @Override
        	        public void handleMessage(Message msg) {
        	        	pd.dismiss();

        				if (foundAdresses.size() == 0) { // if no address found,
        					// display an error
//
//        					 p = new GeoPoint((int) (foundAdresses.get(0).getLatitude() * 1E6),
//        		                        (int) (foundAdresses.get(0).getLongitude() * 1E6));
//
//
        					Dialog locationError = new AlertDialog.Builder(
        							TravellogActivity.this).setIcon(0).setTitle(
        							"Error").setPositiveButton(R.string.ok, null)
        							.setMessage(
        									"Sorry, your address doesn't exist.")
        							.create();
        					locationError.show();

        				} else { // else display address on map
        					for (int i = 0; i < foundAdresses.size(); ++i) {
        						// Save results as Longitude and Latitude
        						// @todo: if more than one result, then show a
        						// select-list
        						Address x = foundAdresses.get(i);
        						latit = x.getLatitude();
        						longi = x.getLongitude();
        					}
        					navigateToLocation((latit * 1000000), (longi * 1000000),myMapView); // display the found address
        				};

        	return  ;

        }

					private void navigateToLocation(double latitude, double longitude,
							MapView myMapView) {
						// TODO Auto-generated method stub
						 p = new GeoPoint((int) (foundAdresses.get(0).getLatitude() * 1E6),
		                        (int) (foundAdresses.get(0).getLongitude() * 1E6));
						MC.animateTo(p);

		                myMapView.invalidate();








protected class MyLocationOverlay extends com.google.android.maps.Overlay {

		@Override
		public boolean draw(Canvas canvas, MapView myMapView, boolean shadow, long when) {
			Paint paint = new Paint();

			super.draw(canvas, myMapView, shadow);
			// Converts lat/lng-Point to OUR coordinates on the screen.
			Point myScreenCoords = new Point();
			myMapView.getProjection().toPixels(p, myScreenCoords);





			paint.setStrokeWidth(1);
			paint.setARGB(255, 255, 255, 255);
			paint.setStyle(Paint.Style.STROKE);

			Bitmap bmp = BitmapFactory.decodeResource(getResources(), R.drawable.marker);

			canvas.drawBitmap(bmp, myScreenCoords.x, myScreenCoords.y, paint);
			canvas.drawText("I am here...", myScreenCoords.x, myScreenCoords.y, paint);