[pierhs]

Define something like this:

Код:

HavePermission[MAX_PLAYERS];

It should reset when the player connects, so add this on OnPlayerConnect:

Код:

HavePermission[playerid] = 0;

Add the cmd:

Код:

if(strcmp(cmd, "/changeskin", true) == 0)
	{
	  if(IsPlayerConnected(playerid))
	  {
	    if(IsValidSkin(skin) || HavePermission[playerid] == 1)
		  	{
			  new skin;
			  tmp = strtok(cmdtext, idx);
			  skin = strval(tmp);
			  SetPlayerSkin(playerid, skin);
			}
		}
		return 1;
	}

And at last u need to make a command that gives the player permission(It should return HavePermission for player to 1)