The Guestmap is supplied to you with a 1280 x 650 pixel map of the world in two colours - blue and yellow. You can either use this map with the guestmap script or you can create your own map image and use that instead.
If you use your own image then you can use more than two colours but I suggest that you keep the number of colours to a minimum in order to keep the size of the image file as small as possible. The image needs to be in gif format to work with the guestmap script.
There are three reasons I can think of as to why you may want to change the map.
So let's get started. The first step in changing the map image is to create your replacement image and save it as img/map.gif. If the image already exists as a gif file then all you need to do is rename (or copy) the existing file. You will also need to know the width and height of your image.
If your map image is 1280 pixels wide and 650 pixels high (ie the image fills the same screen area as the supplied image) then that is all there is to it.
If your image is a different size (very likely if you are using an existing image rather than creating a new one) then you will need to make a couple of additional changes:
This article written by Stephen Chapman, Felgall Pty Ltd.