Checking for NULL with Report_Open - broken?!

[thebatfink]

Hi,

So I have been using this code for ages, and it always used to work. I now just noticed it no longer does. Its possible I have changed some setting which has affected it's behaviour but I don't know what I have done.

Basically on a report I have a field that has the potential to be Null value. I used to test this condition using the Report_Open event and if it was Null I displayed a text box. This was using the following code:

 Private Sub Report_Open(Cancel As Integer)
On Error GoTo Err
DoCmd.SetWarnings False
If IsNull(Me.ManSig) Then
    Me.Label174.Visible = True
    Me.Label209.Visible = True
Else
    Me.Label174.Visible = False
    Me.Label209.Visible = False
End If
DoCmd.SetWarnings True
Exit Sub
 Err:
DoCmd.SetWarnings True
MsgBox Err.DESCRIPTION
End Sub

It now seems to see everything as Null = False?!?! I have tested by setting the field in a record to Null using:

UPDATE [mytable] SET [myfield] = Null;

to ensure the field really does have a null value but it still seems to think that field is Not Null when I open the report. I know the code is firing because I have put in msgboxes to test.
For information, the report is opened from a form using a command box and the following code

 DoCmd.OpenReport stDocName, acPreview, "", "[partno]   = """ + Me.partno + """", acWindowNormal

I was wondering if for some reason it is seeing the field as zero length instead of Null, so I added this code into my Report_Open sub..

 If Me.ManSig = "" Then
 msgbox "I'm empty"
 End if

I also tried using If Len(Me.ManSig & "") = 0 Then.. but in each of cases, whenever I try to test the value for anything other than IsNull, I get an error

Run-time error '2427':
you entered an expression that has no value

I really need to get this working again as it is critical to the functionality of the database. Any ideas would be greatly appreciated. Thank you.

 

[pr2-eugin]

Open method might be too early, try Report_Load.

 

[mdlueck]

In Group By fields in Reports, I have successfully used this to test for a completely empty report to prevent an error message:

=IIf([Report].[HasData],[statuscode],"N/A")

In the case there report has no data to display, "N/A" shows up in the Group By field.