$FUNCNAME$
  USED()
$CATEGORY$
  DATABASE
$SUMMARY$
   Determine whether a database file is in USE
$LANG_RU$
   ,        .
$SYNTAX$
     USED() --> lDbfOpen
$LANG_RU$
     USED() -->     
$RETURNS$
     USED() returns true (.T.) if there is a database file in USE; otherwise,
     it returns false (.F.).
$LANG_RU$
     USED ()   "" (..),   
       ;       ""
     (.F.).
$DESCRIPTION$
     USED() is a database function that determines whether there is a
     database file in USE in a particular work area.  By default, USED()
     operates on the currently selected work area.  It will operate on an
     unselected work area if you specify it as part of an aliased expression.
$LANG_RU$
     USED () -     ,   
             ()
      .   USED()   
     .    USED()    
      ,      ,
      .  (    ).
$EXAMPLES$
       This example determines whether a database file is in USE in
	the current work area:

	USE Customer NEW
	? USED()               // Result: .T.
	CLOSE
	? USED()               // Result: .F.


$LANG_RU$

        ,        
        :

       USE Customer NEW
       ? USED()                                 //  ..
       CLOSE
       ? USED()                                 //  .F.

           USED()  ,
        :

       USE Customer NEW
       USE Sales NEW
       USE Invoices NEW
       SELECT O
       //
       ? Customer --> (USED())                  // : ..
       ? Sales --> (USED())                     // : ..
       ? Invoices --> (USED())                  // : ..
       ? BackOrder --> (USED())                 // : .F.


$SEEALSO$
  SELECT(),ALIAS()
$END$
