Prevent Error Being Thrown When No Messages Exist

I am using the following code to check whether a message exists on the specified queue:




Code Block
DECLARE @RecvReplyMsg NVARCHAR(100);
DECLARE @RecvReplyDlgHandle UNIQUEIDENTIFIER;
BEGIN TRANSACTION;
RECEIVE TOP(1)
@RecvReplyDlgHandle = conversation_handle,
@RecvReplyMsg = message_body
FROM TargetQueue;
END CONVERSATION @RecvReplyDlgHandle;
SELECT @RecvReplyMsg AS ReceivedReplyMsg;
COMMIT TRANSACTION;
GO


How can I prevent errors being thrown when there are no messages waiting on the queue? For example, if I send a message to the queue and run the above twice I get the following:


Msg 8418, Level 16, State 1, Line 11

The conversation handle is missing. Specify a conversation handle.


Thanks