Cognitive Radio Network (CRN) and Cooperative Communication provides a new environment in wireless network which can effectively improve the spectrum efficiency of future wireless network. In this paper, a two phase protocol based cooperative relaying for a secondary user along with decode-and-forward (DF) and amplify-and-forward (AF) relaying system is proposed. In the proposed protocol, a dynamic queuing algorithm is used to access and manage the spectrum from a Primary User (PU) to the Secondary Users (SU) without any conflicts between the cognitive users (CR) or Secondary Users (SU) for accessing the same available spectrum. A Multi Behaviour Node System (MBNS) is used to achieve better outage performance for the secondary system when it fails from a relay selection. The proposed scheme achieves the effective spectrum sharing and hence the overall system performance is improved. The simulation result shows the improvement over DF and AF relaying system.