Enabling headset button automatically during calls I have a Samsung Tab 2, and a mono bluetooth headset. 

The phone shows a bluetooth-connected icon at the top. When I dial any phone number, the headset button is not showing as connected. I have to click the headset button everytime to hear the phone audio in bluetooth headset.

Is there any way to enable headset button automatically during calls when the bluetooth headset is connected?
I don't know if they will work in this case, but maybe you could have a look at apps like Auto Bluetooth, Bluetooth Auto Connect, Automatic Bluetooth Toggle and many more (just look for somethinig like auto bluetooth in Play Store). Maybe there are some apps that can solve your problem.

As far as I know, there is no real built-in way to enable that button.