[Ur] Dynamic form input values

[Taru Karttunen]

Hello

How does one express something like (pseudocode):

<textbox{#Foo} value=<dyn signal={[mysource]}/>/>

i.e. I want to have a dynamic behaviour that modifies the value of a
form field (and mysource is a "source string").

Just using a signal with the xml value does not seem like a good
solution since the value needs to be get+set instead of just set 
to a new value. 

- Taru Karttunen