union query not running properly

[aperture]

hello all-

i have written the following sql statement in the row source of a list box.

SELECT Null AS strUWorMgrName, Null AS strRACF FROM qryAgfcyVisitbyRACF UNION SELECT DISTINCTROW qryAgcyVisiitbyRACF.strUWorMgrName, qryAGYVISITbyRACF.strRACF FROM qryAgcyVisitbyRACF;

when i attempt to execute the statement and fill the list box, i get an error box reading "Syntax Error (Missing Operator) in query expression '()'."

can anyone catch the error?

thanks!

ap