Error for DateAdd formula on blank date field

=IIf(IsError(DateAdd("d",30,[Text44])),"",DateAdd("d",30,[Text44]))

When the above formula is evaluated for a Text44 textbox  with a "" value, I get an error as the output for the second text box.

What can I do make the formula output a blank value?

Thanks

Glen
GPSPOWAsked:
Who is Participating?
I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

SimonCommented:
The problem is that IIF evaluates both parts, even though it only returns a value for one of them.

This is a problem when using calculated controls. I tend to use event handlers that fire after controls are modified to set dependent fields. In this case I'd check that the value in Text44 is a date and only then calculate and populate the dependent field.
0
Rey Obrero (Capricorn1)Commented:
try

= IIf([Text44] & "" = "", "", DateAdd("d", 30, [Text44]))
0
Dale FyeCommented:
Or you could create a function:
Public Function DateAddPlus(Interval as string, Incr as Double, SomeDate as Variant) as Variant

    IF Len(Trim(SomeDate & " ")) = 0 Then
        DateAddPlus = ""
    Else
        DateAddPlus = DateAdd(Interval, Incr, SomeDate)
    End If

End Function

Open in new window

The advantage of using a function is that the function will be evaluated when you go to a new record and when you make a change in the the first date control.  The syntax you would use to call this function within your Control Source would be something like:

=DateAddPlus("d",30,[Forms]![YourFormName].[text44])
0

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
GPSPOWAuthor Commented:
Thanks to all who gave me the good recommendations.

Glen
0
SimonCommented:
I just knocked up a quick test. If the input date field is blank, a simple =DateAdd() calculated field stays blank until a valid date is entered into the input date field. My test used a bound date field to as the input date field. If using unbound fields, using an input mask or validation rule would prevent any non-date values being entered.
0
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
Microsoft Access

From novice to tech pro — start learning today.

Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.