Talking About the Future

Use Will when you decide to do something as you are speaking:

I´ll just stop by my apartment to change clothes, and then I´ll come right over to meet you.

Use Will or Going to for factual information or predictions based on what you know:

You´re going to be out of townm but you'll be back Friday?
My Boss is going to make us work late Friday.
Our Project won´t be finished on time.