Hey Jafri!
I don't know what type of file system you have or if you have a login system, but something like this is easy to do with 
dini. You'll need to download the dini include.
Something like this would work:
Save the pcash on disconnect
Код:
public OnPlayerDisconnect(playerid, reason)
{
	  new file[128], pname[MAX_PLAYER_NAME];
	  GetPlayerName(playerid, pname, sizeof(pname));
	  format(file, sizeof(file), "%s.ini", pname);
      if(!dini_Exists(file))
      {
          dini_Create(file);
      }
	  dini_IntSet(file, "PCash", GetPlayerPCash(playerid));
      ResetPlayerPCash(playerid); //reset Pcash for security
      return 1;
}
 Give the player their PCash when they connect (or add something like this to your login system otherwise anyone with the same name could join and get the pcash)
Код:
public OnPlayerConnect(playerid)
{
	  new file[128], pname[MAX_PLAYER_NAME];
	  GetPlayerName(playerid, pname, sizeof(pname));
	  format(file, sizeof(file), "%s.ini", pname);
      if(dini_Exists(file))
      {
          GivePlayerPCash(playerid, dini_Int(file, "PCash"));
      }
      return 1;
}
 Hope this helps