Why is the InputField not editable?

Dear Forum,

I'm just starting to learn Web Dynpro Java. In the book "SAP NetWeaver Portal" from SAP PRESS, I followed the Web Dynpro example application from chapter 6.4.

When I deploy and execute the project everything looks like in the book, but the InputField is not editable.

The setup is as follows: The InputField has property readOnly set to false, and a value that points to Node1.My_Name of type string which is defined in the context and also has readOnly set to false.

What could possibly be wrong?