public boolean deleteSupplier(Supplier s){
		Boolean isDeleted=null;
		connectionDB();
		String sql="delete from supplier where supplierId=?";
		try {
			ps=conn.prepareStatement(sql);
			ps.setLong(1,s.getSupplierId());
			int rows=ps.executeUpdate();
			isDeleted=rows>0?true:false;
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}finally{
			closeDB();
		}
		
		return isDeleted;
	}