title: process back button press when loading web page
body: <p>I am having problems with the back button in android and need some help.</p>
  
  <p>My application has an activity named 'A'. 
  From 'A', I start new activity named 'B' but don't finish 'A'. 
  From 'B', I start new intent to call web browser. 
  When a user press the back button while the webpage loading isn't complete, it causes my program back to activity 'B'. 
  However I don't want to back to activity 'B', I want to finish B and back to activity 'A' instead. </p>
  
  <p>Does anyone have a solution for this situation? Please help me!
  Thank you very much!</p>