android studio about inserting event on own mobile calendar -

the programme runs error. however, event doesnt insert own mobile's calendar. know reason that?? mobile pentech a880. or there method insert events?

package com.example.lean.myapplication;   public class myactivity extends activity { protected void oncreate(bundle savedinstancestate) {     super.oncreate(savedinstancestate);     setcontentview(r.layout.list_fragment);     button button = (button) findviewbyid(r.id.button);     button.setonclicklistener(new view.onclicklistener() {                                   @override                                   public void onclick(view v) {                                       intent intent = new intent(intent.action_pick, android.provider.mediastore.images.media.external_content_uri);                                       startactivityforresult(intent, 2);                                   }                               }      );     addtocalendar(getapplicationcontext(), "hello","2015/10/10 10:05:33" ); }       public static void addtocalendar(context ocontext, final string title, final string eventstartdate)     {         string eventuristring = null;          long startdate = new date(eventstartdate).gettime();         long enddate = new date(eventstartdate).gettime() + 1000 * 60 * 60; // next 1hr         timezone timezone = timezone.getdefault();          contentvalues eventvalues = new contentvalues();          if (build.version.sdk_int >= 1 && build.version.sdk_int < 13)         {             eventuristring = "content://com.android.calendar/events";              eventvalues.put("calendar_id", 1);             eventvalues.put("title", title);             eventvalues.put("description", "");             eventvalues.put("eventlocation", "");              eventvalues.put("dtstart", startdate);             eventvalues.put("dtend", enddate);             eventvalues.put("eventtimezone", timezone.getdefault().getid());             eventvalues.put("eventstatus", "");             eventvalues.put("visibility", 3);             eventvalues.put("transparency", 0);             eventvalues.put("hasalarm", 1);              uri eventuri = ocontext.getapplicationcontext().getcontentresolver().insert(uri.parse("content://com.android.calendar/events"), eventvalues);             long eventid = long.parselong(eventuri.getlastpathsegment());              string reminderuristring = "content://com.android.calendar/reminders";              contentvalues remindervalues = new contentvalues();              remindervalues.put("event_id", eventid);             remindervalues.put("minutes", 5);             remindervalues.put("method", 1);              ocontext.getapplicationcontext().getcontentresolver().insert(uri.parse(reminderuristring), remindervalues);          }         else if (build.version.sdk_int >= 14 )         {             eventvalues.put(calendarcontract.events.dtstart, startdate);             eventvalues.put(calendarcontract.events.dtend, enddate);             eventvalues.put(calendarcontract.events.title, title);             eventvalues.put(calendarcontract.events.description, "");             eventvalues.put(calendarcontract.events.calendar_id, 3);             eventvalues.put(calendarcontract.events.event_timezone, timezone.getid());              ocontext.getapplicationcontext().getcontentresolver().insert(uri.parse("content://com.android.calendar/events"), eventvalues);         }          toast.maketext(ocontext, "event created on : " + startdate, toast.length_short).show();     }       @override public boolean oncreateoptionsmenu(menu menu) {     // inflate menu; adds items action bar if present.     getmenuinflater().inflate(r.menu.my, menu);     return true; }  @override public boolean onoptionsitemselected(menuitem item) {     // handle action bar item clicks here. action bar     // automatically handle clicks on home/up button, long     // specify parent activity in androidmanifest.xml.     int id = item.getitemid();     if (id == r.id.action_settings) {         return true;     }     return super.onoptionsitemselected(item); } 

}

perhaps didn't ask permissions

     <?xml version="1.0" encoding="utf-8"?>      <manifest xmlns:android="http://schemas.android.com/apk/res/android"...>          ...          <uses-permission android:name="android.permission.read_calendar" />          <uses-permission android:name="android.permission.write_calendar" />          ...      </manifest>