I noticed this error in http://www.allaboutcircuits.com/vol_3/chpt_4/1.html

The main current that is controlled goes from collector to emitter, or from emitter to collector, depending on the type of transistor it is (PNP or NPN, respectively).

it should be NPN or PNP respectively.

at the same link the diagrams showing the current direction for npn and pnp are wrong. the left most diagram should be npn and rightmost diagram should be pnp. Source:

Microelectronic Circuits, Sedra/Smith, 5th edition, pp.393, figure 5.14

 

Please ignore my above correction. i did not realize "electron flow theory" is used rather than "conventional current flow". i am accustomed with conventional current flow.

sorry for any confusion.