* Returns .T. if the file exists and it is possible to open for exclusive use
Function yesexclus
   Lparameters filename
   local IFP
   If .Not. "." $ Alltrim(filename)
      filename = Alltrim(filename) + ".DBF"
   Endif
   If File(Alltrim(filename))
      IFP = Fopen(Alltrim(filename), 2)
      =Fclose(IFP)
      IFP = Iif(IFP > 0, .T., .F.)
   Else
      IFP=.F.
   Endif
   Return IFP