clear field if not a member of related value list

[rivet]

two fields and two tables:

- continent

- country

third table:

- traveller

when a new traveller is created a continent is select from a related pulldown. and then a country is selected from a pulldown that is related to the selected continent.

If the user has selected both and then decides to change the continent. I would like the country to clear. If current country is not a member of the related value list.

My first attempt was a field calc value:

If (

Position ( ValueListItems ( Get ( FileName ) ; "county" ) ; traveler::country ; 1 ; 1 ) =0 ;

"" ; traveler::country )

[Søren Dyhr]

Refresh my memory, which country exists on more than one continent - except Russia???

I think I instead would clear the country field every time someone tampers with the continent selection.

It can be done by making the country field an autoenter calc that replaces existing value with this calc's result:

Evaluate(Case(0;0);ContinentField)

--sd

[rivet]

thanks I will give it a try. And sorry about the geography... I am acctually working with Markets and Districts.