Using excel v.2007

I would like to populate a number of cells with the same answer depending on
what I answer in cells prior to the cells I want with the same answer.

For example. If I answer 'yes' in cell A1, then I would like cells B1
through to G1 to have an answer of 'n/a'.

I'm new to the world of excel, so please can you help. If you need more
info, let me know.

Thanks.