How To Count Across Multiple Tables In A DB?

Thank you in advance for your assitance. I am trying to write a query that will query multiple tables for the same column. All the tables have thsi column "szF11". I am wanting something similar to this:




Code Snippet
SELECT count(ulID)
FROM (dbo.F_ACCOU_Data UNION dbo.F_AGNCY_Data UNION dbo.F_APPEA_Data UNION etc.....)
WHERE szF11 = ' '




Note: ulID is the name of a column that every table has and szF11 is also in every table.

Pseudo Code: I want to count how many ulID's (if there is a row then something is in the ulID column it is never blank) in all the tables that are listed that have a blank in the szF11 column.

I am getting a very cryptic error message and of course I can't find anything in the documentation to help me understand the error.

Thanks,
Erik