Find the Path

Say we have a 4x5 board. Your job is to mark a pathway on that board such that the square you start on is 01. The next square you move to is 02 and the following one is 03 and so on to 20. You may move one square vertically or horizontally, but not diagonally. You may enter each space only once. A simple path would go like this:

01 02 03 04 05
10 09 08 07 06
11 12 13 14 15
20 19 18 17 16

Can you figure out a working path for the following board:

- - - - x
- - x - -
- x - - -
- - - - -

Each of the x's represent 5, 10 and 15 in some unknown order.