How do I calculate an average and exclude the null values?

I have a list of weekly earning values for which I calculate an average weekly value using the AVERAGE command. Some of the weeks have a null value as nothing was earnt. I want to do a comparative average just using the values above zero. Is there a way of using my original table of values that includes the null values and exclude them in some way in the formula or will I just have to create another table and not include the weeks showing nulls?

Thanks for any help.

Wow, that was quick Pepe. Many thanks. So I'd just use AVERAGEIF in place of AVERAGE? My knowledge isn't brilliant so don't be afraid of setting out what I need to do in simple terms!

I think I've cracked it but I'm not allowed to post any links until I've posted a few more times.



Thanks again.