boys

My 9 year old is having issues at school.  Not concentrating or paying attention , not finishing class work or home work  not sitting still.   I don't know what to do about it.  Finally a teacher is seeing what we see at home.  He doesn't pay attention for more than a few minutes at a time.  This kid is NOT stupid though.  I wonder if that is why all the teachers in the past never really said anything about his behavior at school. They always lead us to believe this was all in our heads.  Maybe it was because they are all worn out teachers that don't want to deal with military parents.   His teacher this year says he loves having him in class and that he always volunteers and is always polite and has good manners but he just keeps getting distracted and talking with the kids.   I don't know what to do about this.  I don't know how to reenforce the positive behavior.  We had a wonderful talk a week ago or so and he seemed so in control of his thoughts and his behavior but we are back to this.  It is really making me worry about him and what we can do for him.   I have never believed in ADD or ADHD before but I am seriously wondering if he has this.   I don't even know how to go about making an appointment to talk to a doctor about it?   Feeling a bit lost.