[gtkmm] How to make Entry widget read-only?

[erik_ohrnberger dme net]

Dear Gtkmm list,
	I've got this question, which would appear to be a really easy one.

	I have a display only, non-user editable, Entry field on my dialog.
The question is how to tell the Entry field that this is the case?

	Thanks for your help,
		Erik.