delete query sub & main table compare

[Trevor]

I have a delete query that is suppose to compare the [IDNumber in VMSU-ILT-sub] to the [IDNumber] in [VMSU-ILT-main and if any IDnumber in VMHU-ILT-Sub does not match any IDNumber in VMSU-ILT-Main it is suppose to delete that record(s) from VMSU-ILT-Sub. but it doen't seem to be working, when I run it i get a popup window asking for VMSU-ILT-Main IDNumber criteria

DELETE [VMSU-ILT-Sub].IDNumber, "IDNumber"
FROM [VMSU-ILT-Sub]
WHERE ((("IDNumber")<>[VMSU-ILT-Main].[IDNumber]));

(it is currently runing from the graphical query design)