This has got to be SO easy but even following the Help instructions isn't working. I have a photo of a tractor trailer on a totally white background. I want to make the white background transparent so just the truck shows when I place it in InDesign over a background color. I've tried background eraser and magic eraser and they replace the white with checkerboard. Then I save it as a JPEG, but when I place it the white box is still around the truck. What am I doing wrong?