Hello:

I've learned that the problem is with IIF in VBScript (I thnink!).
Found this code (thanks Sue Mosher):

Public Function IIf(blnExpression, vTrueResult, vFalseResult)
If blnExpression Then
IIf = vTrueResult
Else
IIf = vFalseResult
End If
End Function

and now this expression appears to work:

Item.UserProperties.Find("Age").Value =
IIf([Birthday]"None",DateDiff("yyyy",[Birthday],Date())-IIf(DateDiff("d",CDate(Month([Birthday])
& "/" & Day([Birthday]) & "/" & Year(Date())),Date())0,1,0),"")

Thanks,
Fred

"Fred Boer" wrote in message
...
I am making some progress. This works:
Item.UserProperties.Find("Age").Value = "Hello"

But this generates a "Type Mismatch" error message:

Item.UserProperties.Find("Age").Value =
IIf([Birthday]"None",DateDiff("yyyy",[Birthday],Date())-IIf(DateDiff("d",CDate(Month([Birthday])
& "/" & Day([Birthday]) & "/" & Year(Date())),Date())0,1,0),"")

Still plugging away...

Thanks!

Fred

Fred Boer" wrote in message
...

Hi:

I have a textbox which I want to have filled with the contact person's
age, derived from birthdate using a formula. I have a formula, and have
created a working textbox. If I change the birthdate it fills in the
textbox.

But...

I have existing birthdate data for contacts. The textbox does not appear
to respond to existing data. Is there a way to force the calculation when
I move from one contact to another (on menu using up/down arrows), or
when I open the form for a contact who has an existing birthdate?

Thanks!
Fred