Returns response WS-Action if available
           action -- request WS-Action value.

def getResponseAction(self, ps, action):
        '''Returns response WS-Action if available
           action -- request WS-Action value.
        '''
        opName = self.getOperationName(ps, action)
        if self.wsAction.has_key(opName) is False:
            raise WSActionNotSpecified, 'wsAction dictionary missing key(%s)' %opName
        return self.wsAction[opName]