You are mistaken. Revolution (selamectin) controls heartworm and fleas and (to a lesser extent) ticks. See wikipedia for more: http://en.wikipedia.org/wiki/Selamectin
I see by your profile that you are 15 years old. Are you responsible for your pet's care, or are you researching for your parents? Lonewolf makes an excellent suggestion about Sentinel. It's a heartworm preventive and also helps control fleas. If a flea bites your dog, that flea is rendered sterile and can't reproduce. That really helps keep them from infesting your home and yard. Of course, you then have to worry about the fleas that come from other dogs or other places your dog walks. You can use Frontline in conjunction with Sentinel with no problem. The Dawn dishwashing liquid also works really well, so use that in the meantime until you and your parents can figure out a more permanent solution.
It's possible your property is infested and if so, that will also need to be treated. Have you noticed any fleas in your home? You'll have to vacuum daily and throw away the bags promptly and also need to use flea killing spays on furniture, carpet and drapes.
You are right to ask for help, because fleas can quickly take over your home and yard and make humans just as miserable as your dog.
We have now found 10 to 12 fleas on her every single day. HELP!
For immediate relief, use Kitchen "Dawn" liquid dish soap and give a bath, it will kill fleas and give immeidiate relief, and will not harm the Chi, I own 5 Chi's and thats what the vets in my Texas area advice and it works, you'll see...Get the orignal Blue Liquid Dawn dish soap, not the antibacterial or other colors and scents, the original...works great!!
Holistic way is to put "Brewer's yeast on the dog food" after about 2 wks of eating that on food, the fleas will not bother the dog...you can find powdered Brewer's yeast at the vitiamin store, its a powder...
I have my yard professionally done, and not sure what they use, but the dogs are allowed after a day and night to go out onto yard...treat the yard, usually treats the issue..
But, the Dawn soap is a miracle worker...Give your Chi a big hug for me!
Have you ever tried Sentinel? It's really good for fleas and ticks AND heartworm. Comes in pill form you can bathe your dog without having to wait. Revolution is good too but does not have heartworm protection. If you are concerned about fleas in the dog's or your environment diatomacious (sp?) earth is good to get rid of them and as far as I know it's environmentally friendly and not toxic.
Other folks on here might have more suggestions. I just mentioned what we use on our cats and dogs.
I hope you find something that works.
lonewolf