[Doppeyy]

public OnPlayerCommandText(playerid, cmdtext[])
{

if(!strcmp("/Unjail", cmdtext, true))
{
if(IsPlayerAdmin(playerid)) // so only admins can unjuil people
{
SetPlayerPos(playerid,*Set Your Cords Here Where The Player Spawns After You Unjail Him);
SetPlayerInterior(playerid, 0);
SendClientMessage(playerid, COLOR WHITE ,(or any other colour you want!) "You have been unjailed");
}
return 1;
}

with this you will get a long way i think