Add Column Values

I've been trying to figure this out for the past 2 hours with no luck.

I have two columns with data in the form of text and am trying to add it up so I can make a graph. For example, in Column D, you see positive, negative or mixed. I'd like to figure out an effective way to search Column B for Forum and also search Column D for Positive and get a total.

Column B
Channel
Forum
Forum
Blog
Forum
Online Review Site
Blog
Blog
Blog
Blog
Website Article
Twitter


Column D
Negative
Negative
Negative
Mixed
Positive
Negative
Negative
Negative
Mixed
Positive
Positive
Positive

Feel free to IM me: bikersnm

Thanks!