Francisco,

>i see Rick Strahl and Markus Egger Apps where they dont use the _screen, in place they re use Forms or level superior, in Mere Mortals the default is _screen.
>In case i want use Forms or level superior, could be have a problem?

I think you mean running an MM application with the main form as a Top Level form?! If yes, there are a few places, where you will have to make some changes (not all really MM specific, some of them are necessary in any case):

1) You have to explicitly call the TL form somewhere in the application class at startup.
2) You have to make sure that the main menu is displayed in the TL form (probably change cMenu class).
3) You have to hide the _SCREEN at startup.
4) You can't use the "wallpaper" picture feature for the _SCREEN.
5) You have to set the form classes to ShowWindow = "In Top Level" form

I think this should be most of the work to get MM running with TL forms. Hope I didn't forget anything substantial.

HTH,
Armin