can not start create popup window when activity first start
<pre><code>protected void onCreate(Bundle savedInstanceState) {
    // TODO Auto-generated method stub
    super.onCreate(savedInstanceState);
    setContentView(R.layout.question_layout);
    show_popup();
}

    private void show_popup(){
    LayoutInflater lf = (LayoutInflater)getSystemService(Context.LAYOUT_INFLATER_SERVICE);
    View m_view = lf.inflate(R.layout.popup_question, null);
    m_popup_window = new PopupWindow(m_view,500,150,false);
    m_popup_window.showAtLocation(m_full_page, Gravity.CENTER, 0, 0);
}
</code></pre>

<p>when i click on any button to call for show_popup it work fine but when i want show_popup() call onCreate() it not work. i got an error show on logcat like this</p>

<pre><code>08-22 13:57:36.682: ERROR/AndroidRuntime(21860):     at tesingimage.com.testingimagemain.show_pupup(testingimagemain.java:41)
08-22 13:57:36.682: ERROR/AndroidRuntime(21860):     at tesingimage.com.testingimagemain.onCreate(testingimagemain.java:23)
08-22 13:57:36.682: ERROR/AndroidRuntime(21860):     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
</code></pre>

<p>please help me in advance thank you!</p>
