Public Class cDateiCopy
    Public Shared isCancel as Boolean
    Public Shared Function '...
        isCancel = False

    cDateiCopy.isCancel = True
    Me.Close()

        For intLoopCtr = 1 To intBufferCount + 1
            if isCancel = True then return ' wird von der Abbrechen schaltfäche 
            ' des Form beschrieben
            FileGet(1, strInByte)
            FilePut(2, strInByte)