If they should stop texting for a while--pull back but don't assume the friendship is over. They may suddenly reach out again and of course you can reach out but if they have pulled back for a while try to give them some space but have faith that you will always have a place in each other's heart. Also, how much I instant message my fb friends goes up and down. I have periods of time where I don't message them because I just don't have much to say to them but when something comes up that I think will interest them I will message them again even if there hasn't been much communication in months. Keep in mind, these are long distance high school friends I am talking about. If your friend lives close then maybe you should make an effort to get together in person.