title: Why Back button is not detecting in muti tab activities?
body: <p>I have Main Activity. That has 4 tabs(<code>TabHost</code>). I have overridden <code>onBackPress()</code> in MainActvity , as well As All 4 activities. This button show user a dialog box and for conformation of Exit
  When app start. It show 1st tab. Then if I press back it work fine. But if I go for next 3 tab and then press back, The app stop. <code>OnDestroy()</code> of Main is called. But there is not dialogue for the user.Even noting is print in log cat. That I have written in <code>onBackPressed()</code> method From and of 5 activities including <code>MainActivity</code>.</p>
  
  <p>I have also try <code>onKeyDown()</code> for back key but result is same? Have any one experience the same? Please help me.</p>