I have an iPhone 4S. I really don't know in which basis it shows Answer/Decline buttons when someone calling me. Sometimes it shows both buttons and sometimes it only show the option "Slide to answer".
The scenarios are,
- The iPhone is locked/unlocked
- The iPhone is in normal mode/silent mode
Note: I does not use Voice mail. I just need the "Decline" button in any mode/ any situation, because the mobile mode should not decide to hide the decline button. The owner of the mobile should decide it!