public static ArrayList<databook> showAllInfo(String authorid){
		
		int i=0;
		double d=0;
		
		ArrayList<databook> bkinfo = new ArrayList<databook>();
		
		try{
			contct=connector.getConnection();
			Sttt=contct.prepareStatement("select * from bk where authorid= '"+authorid+"'");
			restl=Sttt.executeQuery();
			while(restl.next()){
				databook bk = new databook();
				bk.Sin(restl.getString("isbn"));
				bk.Ste(restl.getString("title"));
				bk.Sad(i);
				bk.Spe(restl.getString("publishdate"));
				bk.Spce(d);
				bk.Spr(restl.getString("publisher"));
				bkinfo.add(bk);
			}
		}catch(SQLException e){
			bkinfo=null;
		}if(restl!=null){
			try{
    			restl.close();
    			}catch(SQLException e){}
		}
		connector.Close(contct, Sttt);
		return bkinfo;
	}