def booleanValue(value):
    """Return True or False is value is something sensible.
        Else return None."""
    ix = value.find('#')
    if ix != -1:
        value = value[:ix].rstrip()
    lcvalue = value.lower()
    if lcvalue in ['true', 'yes', 'on']:
        return True
    if lcvalue in ['false', 'no', 'off']:
        return False
