Help, I want hide the Cancel button on Dialog.

I guess you wish to have a progressbar without a cancel button, maybe because you have commits in your transaction. Correct?

In this area does Navision actually not comply with Windows guidelines. A Cancel button should always "undo" whatever it had done so far. So if Navision executes a commit the button should change caption to "Stop". This would indicate it might have done something already, but that you can prevent it from doing more...

But it is not possible using the Dialog variable type :-(
I guess you can do it by making your own form but it might be a bit overkill, depending on your problem...