JSON parsing issue not resolved

My LogCat errors are:

    12-31 14:45:14.920: E/WindowManager(3420): Activity com.example.visit.record.My_Task has leaked window com.android.internal.policy.impl.PhoneWindow$DecorView@4054ed00 that was originally added here
    12-31 14:45:14.920: E/WindowManager(3420): android.view.WindowLeaked: Activity com.example.visit.record.My_Task has leaked window com.android.internal.policy.impl.PhoneWindow$DecorView@4054ed00 that was originally added here
    12-31 14:45:14.920: E/WindowManager(3420):  at android.view.ViewRoot.<init>(ViewRoot.java:277)
    12-31 14:45:14.920: E/WindowManager(3420):  at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:148)
    12-31 14:45:14.920: E/WindowManager(3420):  at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:91)
    12-31 14:45:14.920: E/WindowManager(3420):  at android.view.Window$LocalWindowManager.addView(Window.java:433)
    12-31 14:45:14.920: E/WindowManager(3420):  at android.app.Dialog.show(Dialog.java:288)
    12-31 14:45:14.920: E/WindowManager(3420):  at com.example.visit.record.My_Task$GetTaskDetails.onPreExecute(My_Task.java:137)
    12-31 14:45:14.920: E/WindowManager(3420):  at android.os.AsyncTask.execute(AsyncTask.java:391)
    12-31 14:45:14.920: E/WindowManager(3420):  at com.example.visit.record.My_Task.onCreate(My_Task.java:105)
    12-31 14:45:14.920: E/WindowManager(3420):  at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1093)
    12-31 14:45:14.920: E/WindowManager(3420):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1785)
    12-31 14:45:14.920: E/WindowManager(3420):  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1842)
    12-31 14:45:14.920: E/WindowManager(3420):  at android.app.ActivityThread.access$1500(ActivityThread.java:132)
    12-31 14:45:14.920: E/WindowManager(3420):  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1038)
    12-31 14:45:14.920: E/W