RFC Adapter fails to start

Hi All

When ever i am trying to start RFC Adapter it fails and gives an exception as given below

Module 'com.sap.aii.rfcadapter.core.RfcAdapterModule' created, version 1.1.0002

Initialized module rfc_adapter

Started module rfc_adapter

Adapter engine startup procedure finished: 10 modules started successfully

Adapter engine running...

>>RfcAdapter> Wed Apr 21 20:56:17 IST 2004>>

> cannot initialize exception manager, exception: java.lang.NoClassDefFoundError: com/sap/mw/jco/JC

O$Exception

>>RfcAdapter> Wed Apr 21 20:56:17 IST 2004>>

> stopping RFC Adapter...

>>RfcAdapter> Wed Apr 21 20:56:17 IST 2004>>

> RFC Adapter stopped