Field properties - Mandatory / Readonly

Hi,

A couple of questions regarding field properties :

Mandatory - setting does it only set the blue-asterix so no check at save - do you have to program that ? By check and raise a Message.

Readonly - some fields like TextEdit  it is possible to bind the property for Readonly to a field (besides true and false) - but an amount field I have only the choice of true and false - so for our usecase   it is not possible to set this amount field dynamically ?

I appreciate an answer for one or both questions.

Regards

Jeroen Cosijnse