only allow one party per player

src/gibstick/bukkit/discosheep/DiscoSheep.java

@@ -51,7 +51,9 @@ public final class DiscoSheep extends JavaPlugin {
 		}
 	}
 
-	public void startDisco(Player player) {
+	public void startParty(Player player) {
+		if (!hasParty(player.getName())) {
 			new DiscoParty(this, player).startDisco();
 		}
 	}
+}

src/gibstick/bukkit/discosheep/DiscoSheepCommandExecutor.java

@@ -16,7 +16,7 @@ public class DiscoSheepCommandExecutor implements CommandExecutor {
 	@Override
 	public boolean onCommand(CommandSender sender, Command cmd, String label, String[] args) {
 		if (sender instanceof Player) {
-			parent.startDisco((Player)sender);
+			parent.startParty((Player)sender);
 		}
 		return true;
 	}