'Add a permission to a queue.
:type queue: :class:`boto.sqs.queue.Queue`
:param queue: The queue object
:type label: str or unicode
:param label: A unique identification of the permission you are setting.
Maximum of 80 characters ``[0-9a-zA-Z_-]``
Example, AliceSendMessage
:type aws_account_id: str or unicode
:param principal_id: The AWS account number of the principal
who will be given permission.  The principal must have an
AWS account, but does not need to be signed up for Amazon
SQS. For information about locating the AWS account
identification.
:type action_name: str or unicode
:param action_name: The action.  Valid choices are:
* SendMessage
* ReceiveMessage
* DeleteMessage
* ChangeMessageVisibility
* GetQueueAttributes
:rtype: bool
:return: True if successful, False otherwise.'

def add_permission(self, queue, label, aws_account_id, action_name):

    params = {'Label': label, 'AWSAccountId': aws_account_id, 'ActionName': action_name}
    return self.get_status('AddPermission', params, queue.id)
