Replacing White With Transparent

1. Open your Fireworks image and go to Modify->Canvas Color.
2.Click on the option Transparent from the Canvas Color window. Now any parts of your image that isn’t covered with any objects will display as a white and grey checkerboard pattern
3. Go to File->Save As. Choose ".gif" as your file type and save.
4.From the color palette and under the Transparency window select ‘Alpha transparency’.
5. Click the eyedropper icon next to the transparency type. Now from your image preview click within the area you want to keep white.
5.Select the Magic wand tool from the tool bar. Then click the layer with the white space. Select your white area using the magic wand and press Delete.