def changeFieldState( user, to, field ):
    
    if tooDistant( user.home.x, user.home.y, field.x, field.y):
        raise RDeny, loc("WONT_GO_SO_FAR")
    
    if not validSequence( field.state, to):
        raise RDeny, loc("NOT_VALID_REQUEST")

    resource_err = checkResources( user, to )
    if resource_err not ""( field.state, to):
        raise RDeny, loc( resource_err )

    dbConnection.set( field , "state" , to )


def loc(text):
    return locale.getText(text)


class RDeny(Exception):
    pass