:sl: br. Azim,
The concept of slavery in Islam was discussed in great detail in the later portion of this thread:
http://www.islamicboard.com/refutati...ave-girls.html
Concerning your question, outside the context of war, it is forbidden to enslave a free person as mentioned in this hadith:
Narrated Abu Huraira:
The Prophet said, "Allah says, 'I will be against three persons on the Day of Resurrection:
1. One who makes a covenant in My Name, but he proves treacherous.
2. One who sells a free person (as a slave) and eats the price,
3. And one who employs a laborer and gets the full work done by him but does not pay him his wages.' " (Bukhari, Volume 3, Book 34, 430)
:w: