Understaning the FBA

I need assistance, as I am having trouble with understanding FBA. After reading the presentation Functional Behavior Assessment (http://www.behavioradvisor.com/FBA.html), respond to the following case and questions:

Scenario: Johnny is a third grade student with ADHD and has an IEP. He continues to hit other students on the playground. He has been given consequences for his behavior on multiple occasions. There does not appear to be change in his behavior. You are a special education teacher and have been asked to help Johnny’s general education teacher.

What are your first steps?
What is the purpose of conducting an FBA?
What do you think is the function of Johnny’s behavior? (You can make a hypothesis)
What would Johnny’s behavior intervention plan look like?
Discuss any experiences you have had with behavior management and how you plan on using best practices in behavior and classroom management to create an effective learning environment.