public boolean inseertSupplier(Supplier s){
		Boolean isInserted=null;
		connectionDB();
		String sql="insert into supplier values(supplier_seq.nextVal,?,?,?,?,?)";
		try {
			ps=conn.prepareStatement(sql);
			ps.setString(1, s.getSupplierName());
			ps.setString(2, s.getSupplierDescrible());
			ps.setString(3,s.getLinkMan());
			ps.setString(4, s.getTelphone());
			ps.setString(5, s.getAddress());
			int rows=ps.executeUpdate();
			isInserted=rows>0?true:false;
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}finally{
			closeDB();
		}
		return isInserted;
	}