How to scroll Android Listview to the bottom always

BBChatViewHost.java

    public void scrollBottom() {
        // scroll bottom requires posting a runnable to the listView
        // in the case of items loading by themselves dynamically
        // there may be sync issues and scrolling won't be proper
        m_bNeedScrollToBottom = false;
        if (m_listView.getLastVisiblePosition()-m_listView.getFirstVisiblePosition() <= m_listView.getCount())
            m_listView.setStackFromBottom(false);
        else
            m_listView.setStackFromBottom(true);
        BBUILoop.getInstance().delayPost(new Runnable() {
            @Override
            public void run() {
                int nCount = mItemHostSection.getCount();
                BBAppLogger.i("Want Scroll bottom:%d", nCount);
                if (nCount > 0 && m_listView != null) {
                    m_listView.clearFocus();
                    m_listView.setSelection(m_listView.getAdapter().getCount() - 1);

                    // This seems to work
                    m_listView.post(new Runnable() {
                        @Override
                        public void run() {
                            m_listView.setSelection(m_listView.getAdapter().getCount() - 1);
                        }
                    });
                }
            }
        }, 400);
    }

why would you wanna scroll to the bottom?