error in asynctask : Only the original thread that created a view hierarchy can touch its views

``` 06-18 16:50:24.733: W/dalvikvm(1086): threadid=11: thread exiting with uncaught exception (group=0x40015560) 06-18 16:50:24.815: E/AndroidRuntime(1086): FATAL EXCEPTION: AsyncTask #3 06-18 16:50:24.815: E/AndroidRuntime(1086): java.lang.RuntimeException: An error occured while executing doInBackground() 06-18 16:50:24.815: E/AndroidRuntime(1086): at android.os.AsyncTask$3.done(AsyncTask.java:200) 06-18 16:50:24.815: E/AndroidRuntime(1086): at java.util.concurrent.FutureTask$Sync.innerSetException(FutureTask.java:274) 06-18 16:50:24.815: E/AndroidRuntime(1086): at java.util.concurrent.FutureTask.setException(FutureTask.java:125) 06-18 16:50:24.815: E/AndroidRuntime(1086): at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:308) 06-18 16:50:24.815: E/AndroidRuntime(1086): at java.util.concurrent.FutureTask.run(FutureTask.java:138) 06-18 16:50:24.815: E/AndroidRuntime(1086): at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1088) 06-18 16:50:24.815: E/AndroidRuntime(1086): at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:581) 06-18 16:50:24.815: E/AndroidRuntime(1086): at java.lang.Thread.run(Thread.java:1019) 06-18 16:50:24.815: E/AndroidRuntime(1086): Caused by: android.view.ViewRoot$CalledFromWrongThreadException: Only the original thread that created a view hierarchy can touch its views. 06-18 16:50:24.815: E/AndroidRuntime(1086): at android.view.ViewRoot.checkThread(ViewRoot.java:2932) 06-18 16:50:24.815: E/AndroidRuntime(1086): at android.view.ViewRoot.requestLayout(ViewRoot.java:629) 06-18 16:50:24.815: E/AndroidRuntime(1086): at android.view.View.requestLayout(View.java:8267) 06-18 16:50:24.815: E/AndroidRuntime(1086): at android.view.View.requestLayout(View.java:8267) 06-18 16:50:24.815: E/AndroidRuntime(1086): at android.view.View.requestLayout(View.java:8267) 06-18 16:50:24.815: E/AndroidRuntime(1086): at android.view.View.requestLayout(View.java:8267) 06-18 16:50:24.815: E/AndroidRuntime(1086): at android.widget.RelativeLayout.requestLayout(RelativeLayout.java:257) 06-18 16:50:24.815: E/AndroidRuntime(1086): at android.view.View.requestLayout(View.java:8267) 06-18 16:50:24.815: E/AndroidRuntime(1086): at android.widget.AbsListView.requestLayout(AbsListView.java:1102) 06-18 16:50:24.815: E/AndroidRuntime(1086): at android.view.View.setFlags(View.java:4641) 06-18 16:50:24.815: E/AndroidRuntime(1086): at android.view.View.setVisibility(View.java:3116) 06-18 16:50:24.815: E/AndroidRuntime(1086): at com.mythrii.tripview.BusFrom$DownloadImageTask.doInBackground(BusFrom.java:274) 06-18 16:50:24.815: E/AndroidRuntime(1086): at com.mythrii.tripview.BusFrom$DownloadImageTask.doInBackground(BusFrom.java:1) 06-18 16:50:24.815: E/AndroidRuntime(1086): at android.os.AsyncTask$2.call(AsyncTask.java:185) 06-18 16:50:24.815: E/AndroidRuntime(1086): at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:306) 06-18 16:50:24.815: E/AndroidRuntime(1086): ... 4 more 06-18 16:50:30.571: E/WindowManager(1086): Activity com.mythrii.tripview.BusFrom has leaked window com.android.internal.policy.impl.PhoneWindow$DecorView@4062bcc0 that was originally added here 06-18 16:50:30.571: E/WindowManager(1086): android.view.WindowLeaked: Activity com.mythrii.tripview.BusFrom has leaked window com.android.internal.policy.impl.PhoneWindow$DecorView@4062bcc0 that was originally added here 06-18 16:50:30.571: E/WindowManager(1086): at android.view.ViewRoot.<init>(ViewRoot.java:258) 06-18 16:50:30.571: E/WindowManager(1086): at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:148) 06-18 16:50:30.571: E/WindowManager(1086): at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:91) 06-18 16:50:30.571: E/WindowManager(1086): at android.view.Window$LocalWindowManager.addView(Window.java:424) 06-18 16:50:30.571: E/WindowManager(1086): at android.app.Dialog.show(Dialog.java:241) 06-18 16:50:30.571: E/WindowManager(1086): at android.app.ProgressDialog.show(ProgressDialog.java:107) 06-18 16:50:30.571: E/WindowManager(1086): at android.app.ProgressDialog.show(ProgressDialog.java:90) 06-18 16:50:30.571: E/WindowManager(1086): at android.app.ProgressDialog.show(ProgressDialog.java:85) 06-18 16:50:30.571: E/WindowManager(1086): at com.mythrii.tripview.BusFrom.onCreate(BusFrom.java:109) 06-18 16:50:30.571: E/WindowManager(1086): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047) 06-18 16:50:30.571: E/WindowManager(1086): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1611) 06-18 16:50:30.571: E/WindowManager(1086): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1663) 06-18 16:50:30.571: E/WindowManager(1086): at android.app.ActivityThread.access$1500(ActivityThread.java:117) 06-18 16:50:30.571: E/WindowManager(1086): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:931) 06-18 16:50:30.571: E/WindowManager(1086): at android.os.Handler.dispatchMessage(Handler.java:99) 06-18 16:50:30.571: E/WindowManager(1086): at android.os.Looper.loop(Looper.java:130) 06-18 16:50:30.571: E/WindowManager(1086): at android.app.ActivityThread.main(ActivityThread.java:3683) 06-18 16:50:30.571: E/WindowManager(1086): at java.lang.reflect.Method.invokeNative(Native Method) 06-18 16:50:30.571: E/WindowManager(1086): at java.lang.reflect.Method.invoke(Method.java:507) 06-18 16:50:30.571: E/WindowManager(1086): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839) 06-18 16:50:30.571: E/WindowManager(1086): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597) 06-18 16:50:30.571: E/WindowManager(1086): at dalvik.system.NativeStart.main(Native Method) ```