The bad news is that you can't do anything in camera to get that result. The good news is that once you understand the possibilities you'll appreciate being able to control how your prints get framed (cropped). Your camera produces images in a 3:4 ratio while a 4 X 6 is a 2:3 ratio so if you don't know in advance that you need to crop some from the top, bottom, or both to make your image fit the 2:3 ratio & frame too tightly when taking the photo you're in trouble. Learn to shoot in a way that allows cropping to match common print sizes, and find a simple editing program to crop in computer. This should be standard practice because even though you may want a 4 X 6 now down the road you might want a 5 X 7 so keep your options open.
If you don't have an editing program that easily does this & you're on a PC download Picasa which is an excellent program for this & it's free. Once you have it running select one of your existing photos, select "crop" from the menues on the first tab & then play around with the different options Picasa has built in to see the effects to your image. NOTE that it won't throw away the data outside the crop box even though it may look like it has. You always have the option to "undo crop". Once you get a result you like you "export" & create a new file cropped as seen on screen WITHOUT modifying the original file.
"A skill is developed through constant practice with a passion to improve, not bought."
