public String getKEGGDrug(int idx) {
		for (ExternalIdentifier eid: drugList.get(idx).getExternalIdentifiers().getExternalIdentifier()) {
			//System.out.println(eid.getResource()+"\t"+eid.getIdentifier());
			if (eid.getResource().equalsIgnoreCase("KEGG Drug"))
				return eid.getIdentifier();
		}
		return null;
	}