[Universal]

pawn Code:

// in the OnPlayerRequestClass
SetPVarInt(playerid, "classID", classid);

// in the OnPlayerRequestSpawn
switch(GetPVarInt(playerid, "classID"))
{
     case 27 .. 31 
     {
          if(!IsPlayerAdmin(playerid))
               return SendClientMessage(playerid, -1, "This class is for admins only.");

          // Do the rest of the code here
     }
}