Problems with Pass Through Query

[Hemish]

Hi,

Just need some help i have a pass through query updating a sql table. (See below at query)

UPDATE WATFORD_SHORT_PACK
SET SH_ORDERADJUST = 1
WHERE (((WATFORD_SHORT_PACK.SH_ORDERADJUST)=0 Or (WATFORD_SHORT_PACK.SH_ORDERADJUST) Is Null) AND (WATFORD_SHORT_PACK.SH_REF)=[Forms]![frmOrderReverse]![cboSON] Or [Forms]![frmOrderReverse]![cboSON] Is Null);

Am getting an error

ODBC - Call failed

[Microsoft][ODBC SQL Server Driver][SQL Server] Line 3: Incorrect syntax near '!', (#170)

I think it does not like the form criteria but not too sure. Has any one got any idea updating a pass through query with a form as a criteria?

Thanks in Advance