public int getIdxNum() throws Exception{
		Connection conn = null;
		PreparedStatement pstmt = null;
		ResultSet rs = null;
		int x = 0;
		try{
			conn=getConnection();
			String sql = "select max(idx) from travel";
			pstmt = conn.prepareStatement(sql);
			rs = pstmt.executeQuery();
			if(rs.next()){
				x = rs.getInt(1) +1;
			}
			
		}catch(Exception ex){
			ex.printStackTrace();
		}finally{
			if(rs!=null)try{rs.close();}catch(SQLException ex){}
			if(pstmt!=null)try{pstmt.close();}catch(SQLException ex){}
			if(conn!=null)try{conn.close();}catch(SQLException ex){}
		}
		return x;
	}