Deleting the row in database is not working.How to get the ID of the row i clicked?

Each row have a id and phone number. I know the position and id are differing. but i got the id of the position through getitemID. and still not working.

How to get the ID of the row i clicked?

              public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_read);
    mainListView = (ListView) findViewById( R.id.mainListView );
   // DatabaseHandler db = new DatabaseHandler(this);

    /**
     * CRUD Operations
     * */


    ArrayList<String> planetList = new ArrayList<String>();

    // Reading all contacts

    contacts = db.getAllContacts();

    for (Contact cn : contacts) {
        log = "ID"+cn.getID()+"Phone: " + cn.getPhoneNumber();


        // Writing Contacts to log
        planetList.addAll( Arrays.asList(log) );
    }

    listAdapter = new ArrayAdapter<String>(this, R.layout.simplerow, planetList);
    mainListView.setAdapter( listAdapter );
    registerForContextMenu(mainListView);
}

            public boolean onContextItemSelected(MenuItem item)
       {  
        AdapterView.AdapterContextMenuInfo info =(AdapterView.AdapterContextMenuInfo)item.getMenuInfo();
        try
        {

        //  info.position will give the index of selected item

                        if(item.getTitle()=="DELETE")
                        { 
                            Contact cn= new Contact();

                            //cn._id=info.position+1; 

                        cn._id= Math.abs((int)listAdapter.getItemId(info.position));
                             db.deleteContact(new Contact(cn._id,cn._phone_number));
                            listAdapter.remove(listAdapter.getItem(info.position));

                            listAdapter.notifyDataSetChanged();

                        }  
                        else
                        {
                            return false;
                        }  

                        return true;  
           }  
        catch(Exception e)
        {
                return true;
        }
    }

}  

DELETE CODE

          void deleteContact(Contact contact) {

        SQLiteDatabase db = this.getWritableDatabase();

     String DELETE_ID= "DELETE FROM " + TABLE_CONTACTS +"    WHERE"+""+KEY_ID+"="+contact._id;     

  db.execSQL(DELETE_ID);

}