After reading the question "Is a cancel button necessary for a web form?", I still ask myself, whether the same applies to a Windows form/dialog box.
Consider the following dialog box:
Compared to the following mockup:
Although I never did omit the Cancel button until now, I have the feeling, that the user might well enough know that the upper right red "X" is here to cancel any dialog.
So I'll effectively give him 2 identical options to cancel (red "X" and cancel button) whereas he only gets one option to store (the OK button).
My question is:
Do you think it is a good idea to remove the cancel button in order to simplify my dialog boxes?
What about omitting the "X" instead?