How can we introduce this new puppy to my chihuahua?

I have a two year old chihuahua. We just recently brought in a boxer puppy. Her tail was wagging but when the boxer started boxing at her with its paws. She started to throw a fit. Then we just let them be in the same room withoutinteracting with each other,but later on my chihuahua wanted to get down and be near the puppy that was playing. We never let them close enough to phisically ever be able to hurt each other. My chihuahua was waggin her tail and barking and wanted to play. I figure since her tail is waggin she does want to play,but her bark makes it seem less playful. The puppy is more playful then I think she is usually used to,and its also quite a bit bigger than her.She has only really been around a few dogs that she can put up with. The one was my 5 year old boxer but she grew up with her.The other were older dogs.With this new puppy I am not sure as what I should do? Should we just keep them in the same room and just get used to each other being there or put them on there leashes and let the interact and see what happens? Your help would be very appericiated THANKS!

you should let them play, just watch them carefully. both dogs are small enough not to cause harm to one another if the fight they fight just stop it. one of the dogs is going to have to be the alpha dog. let them figure it out. most likely the boxer puppy will copy the chihuahua. the boxer does just want to play, and most animals are good with little ones so dont worry about them hating each other. they need to learn to get along now before the boxer grows up and is strong enough to seriously injure your other dog. if they still dont like each other after several months, then I suggest you have an inside and an outside dog

I am a Veterinary Technican, and I would do as poisonpixie03 said above. Although, the Boxer pup you should watch. I am saying this since the breed is very strong from birth, with that wide skull, and It can do damage to a Chihuahua. I would suggest letting them be together in a open area, where you can control the situation. I am sure since it is a puppy, it will be submissive more then anything, if It was a older dog I'd have more worry.
I would also, if you can, place them in a space were they cannot get to one another, but they can still smell & see.