Validating based on data in Parent Form and Subform

[garo]

Hi,
Windows MSAccess2003 is not recognizing the subform field that I want to include in my validation.

The Main form has an Account# as PrimaryID and a Start Date & End Date.
The subform has a one-to-many relationship on the Account#, and also has the Detail Budget Data.

I would like to validate a statment that will prohibit updating a budget record if the dates are not filled in (BeforeUpdate):
Macro Condition:
[Start Date] is null AND [Budget Detail] Is Not Null
Macro Action: MsgBox "Need to enter Dates if entering Budget data"
Macro Action: CancelEvent

How can I get Access to recognize the subform field for this type of comparison?

Much obliged for any assistance.

[MMcCarthy]

The subform object has two events only and enter and exit event. In the enter event you need to put something like the following:

Something like ...

Private Sub subformObjectName_Enter()
 
    If IsNull(Me.StartDate) OR IsNull(Me.EndDate) Then
        MsgBox "You must enter a StartDate and EndDate", vbOKOnly
        Me.StartDate.SetFocus
    End If
 
End Sub