API UnitInBattleground

Returns the unit index if the unit is in your battleground.
 position = UnitInBattleground(unit)
==Parameters==
===Arguments===
:;unit: : UnitId
===Returns===
:;position: - The position in the battleground raid of the specified unit, "nil" if outside of the battleground, and 0 if "unit" is "player" and player is the last person left standing inside of a finished battleground.
==Example==
 local position = UnitInBattleground("player");
 ChatFrame1:AddMessage('Position in battleground raid: ' .. (position or "(?)"));
====Result====
:Prints the player's position number in the battleground raid. e.g. (depending on number left in battleground raid when call is made)
 Position in battleground raid: (?)
 Position in battleground raid: 0
 Position in battleground raid: 12
==Details==
* If 'UnitInBattleground("player")' call is made ...
 Returns nil if outside of a battleground.
 Returns '0' if you are the last person inside of a battleground 
 after the match is over, and everybody else has left.
 Returns 1-#, where # is the maximum number of players allowed 
 in the battleground raid.