[SOLVED] How to change my byline from "by" to "posted by"

Greetings, this is my first post so please be kind

My blog is www.nfcdata.com/blog and I want to change my "by" from BY JOHN SMITH to POSTED BY JOHN SMITH.

All help welcomed.

Kind thanks,

kgm

have you looked at the theme options?

Wow I feel stupid. Any way to change old posts?

Now I feel dumber! One control panel fix changed ALL my posts perfectly. You guys are the best!