You awaken in unfamiliar surroundings as a plate of food clatters to the ground. Your sleepy eyes open to see someone exiting the room, and you hear the clank of a door locking. You realize that you’ve been taken prisoner. Later, you hear a tapping which you realize is an attempt by a fellow prisoner elsewhere in the prison to communicate with you. The code is a series of 1 to 5 taps, a short pause, then 1 to 5 taps, then a long pause. You start recording the message as a series of 2 digit numbers. Commas represent longer gaps.
What is the message, and for bonus points who is the other prisoner?

Mouse over for a hint:

44 23 24 43 , 14 34 33 44 , 31 34 34 13 , 31 24 13 15 , 35 24 43 32 34 ,
12 15 11 13 23 , 24 , 13 33 15 52 , 24 , 43 23 34 45 31 14 , 23 11 51 15 ,
44 11 13 15 33 , 44 23 11 44 , 31 15 21 44 , 44 45 42 33 ,
11 44 , 11 31 12 45 41 45 15 42 41 45 15