Do some reading (see below). You can't use Lilac, or anything else that would grow outdoors in your climate, indoors. Won't survive. They need the cold winter to go dormant, and the gradual cooling and warming in the fall and spring, as well as natural humidity, the sun, rain, nutrients in the ground and a few other things. You don't just grow trees (bonsai) like house plants, there's a whole other learning curve to go by and here's a place to start for basics - www.bonsai4me.com. For more information on what you can grow inside (only tropicals) go to bonsaihunk.us/cultural.html, and for outdoors evergreengardenworks.com.