Global Metadata Change.

This may seem like a silly question, but I haven't been able to figure out or find a solution anywhere. I'm looking to be able to choose all the photos within a project and a meta data category and enter text to apply to all of them with one step. For instance, I'd like to be able to credit myself with all the photos I've taken, or add the same copyright text.

Selecting all the photos and then filling in the text as described only changes one of the files, not all of them. Does anyone know how to deal with this other than going to each individual and having the smart field generator thing fill the categories in after a few letters? It'd save me a respectable amount of time with being able to change a couple hundred photos at the get-go in a few steps, or even groups in one step.