Null Value

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Don - 03 Jul 2005 19:41 GMT

I have code in a combobox AfterUpdate that I want to update a yes/no field if
the user enters certain values in the Diagnoses field. The problem I am
having is if the user makes a mistake and deletes the value He/She chose in
the combobox creating a null value, I get an error "Runtime error 94",
"Invalid use of Null".

I have tried several ways to fix this but none are working. The following is
the code:

Private Sub Diagnoses_AfterUpdate()

Dim stDiagnosesName As String

stDiagnosesName = [Diagnoses]

If stDiagnosesName = "Diabetes" Then
CronicCare = "Yes"

ElseIf stDiagnosesName = "Hypertension" Then
CronicCare = "Yes"

ElseIf stDiagnosesName = "Seizure Disorder" Then
CronicCare = "Yes"

ElseIf stDiagnosesName = "Asthma/COPD" Then
CronicCare = "Yes"

ElseIf stDiagnosesName = "Dialysis" Then
CronicCare = "Yes"

Else: CronicCare = "No"
End If
End Sub

How can I fix this problem?

Thanks,

Dennis

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Rick Brandt - 03 Jul 2005 19:49 GMT

> I have code in a combobox AfterUpdate that I want to update a yes/no
> field if the user enters certain values in the Diagnoses field. The
> problem I am having is if the user makes a mistake and deletes the
> value He/She chose in the combobox creating a null value, I get an
> error "Runtime error 94", "Invalid use of Null".

You can't assign Null to a String variable. Instead use...

stDiagnosesName = Nz([Diagnoses],"")

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I don't check the Email account attached
to this message. Send instead to...
RBrandt at Hunter dot com

Reply to this Message

Don - 03 Jul 2005 21:56 GMT

Rick,

Your solution worked well.

Signature

Thanks,

Dennis

> > I have code in a combobox AfterUpdate that I want to update a yes/no
> > field if the user enters certain values in the Diagnoses field. The
[quoted text clipped - 5 lines]
>
> stDiagnosesName = Nz([Diagnoses],"")

Reply to this Message

Allan Murphy - 04 Jul 2005 07:33 GMT

Dennis

Just a comment, instead of using the IF statements consider using the CASE
statement. Access has limit to how many level of IFs that it can handles

--
Allan Murphy
Email: allanmurphy@unwired.com.au

> I have code in a combobox AfterUpdate that I want to update a yes/no field if
> the user enters certain values in the Diagnoses field. The problem I am
[quoted text clipped - 35 lines]
>
> Dennis

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