Adhoc networks uses mobile nodes to communicate among itself in which it does not have any fixed infrastructure like access point or base station. Due to dynamic network topology MANET security is a challenging task. Most of the routing protocols in MANET assumes a cooperative environment for communication. But, in the presence of malicious nodes, providing security to MANET is critical issue. Due to the increasing applications of MANET building an effective intrusion detection system are essential. This paper addresses using an intelligent approach for intrusion detection in MANET using cross layer technique. We show an paradigm of SVMs, FDAs and AIS approaches for intrusion detection in terms of classification accuracy.