This is how I do it.
1. Resize all the photos to 800 x 600.
2. Create thumbnails at 120 x 100.
3. Upload all the images.
4. Copy the following piece of code at the top of your gallery ...
5. For each image use the following code ...
You will need to replace 'URL of image' with the location of the image file. Replace 'Window header' with the text you want to appear at the top of the image window. Replace "URL of thumbnail file" with the location of the relevant thumbnail.