Access Query

I need to query a field to findout if it has the word "McAfee" or nothing at all. I can get it to look for McAfee or something else, but I'm stumped on looking for blank records.

Any ideas?

Thanks

SELECT * FROM MyTable WHERE IsNull(MyField);

To be a bit more specific

Select * from Table
where fieldToQuery = 'McAfee'
OR fieldToQuery is null
OR fieldToQuery = ''


Last one is to check for empty string.