how to cite this journal article

Hi

I need help.

I was able to cite it perfectly but then now I have this problem

 On reference list:
boyd, D., & Ellison, N. B. (2007). Social network sites: Definition, history, and scholarship. Journal of Computer-Mediated Communication, 13(1), 210-230. 

In text

The first social network site to exist was Six Degrees.com (1997) which allowed its users to create profiles and list their friends (D. boyd & N. B. Ellison, 2007).

Why is this, I tried inputting it many times today and it doesn’t work. 

APA style btw

End Note X6

Oh, it finally worked! thanks anyway :smiley:

Jo Leen