SET HELP TO My_HELP.CHM
SET HELP ON

...
DEFINE PAD HELP OF _MSYSMENU PROMPT "\<Помощь" COLOR SCHEME  3  ;
	KEY ALT+F1, "ALT+F1"
ON PAD HELP OF _MSYSMENU ACTIVATE POPUP m_help
....
DEFINE POPUP m_help MARGIN RELATIVE SHADOW COLOR SCHEME  4 
DEFINE BAR  1  OF m_help PROMPT "\Справка" ;
	KEY F1, "F1"
ON SELECTION BAR  1  OF m_help  Show_Help()

FUNCTION Show_Help()
IF TYPE("_SCREEN.ActiveForm.HelpContextID") = "N" AND  _SCREEN.ActiveForm.HelpContextID >  0 
	HELP ID _SCREEN.ActiveForm.HelpContextID
ELSE
	HELP
ENDIF
ENDFUNC