[WLST] troubles running example from wls 10 doc

Hi all,

starting from http://e-docs.bea.com/wls/docs100/config_scripting/monitoring.html
I put together the below WLST script:

def monitorServerState():

    waitTime=5000
    THRESHOLD=100000000
    
    serverNames = getRunningServerNames()
    domainRuntime()
    for name in serverNames:            
        print '#### Now checking ' + name.getName()            

        try:           
            cd("/ServerRuntimes/" + name.getName() +
"/JVMRuntime/" + name.getName())            
        except WLSTException,e:                
            # this typically means the server is not active, just ignore        
       
            pass            
        heapSize = cmo.getHeapSizeCurrent()            
        if heapSize > THRESHOLD:            
            # do whatever is neccessary, send alerts, send email etc            
   
            print '#### WARNING: The HEAPSIZE is Greater than the Threshold'    
       
        else:                
            print heapSize        
            java.lang.Thread.sleep(waitTime)

        slBean = getSLCRT(name)    
        status = slBean.getState()    
        print '#### Status of Managed Server is '+ status    

where

def getRunningServerNames():    
    domainConfig()    
    return cmo.getServers()

def getSLCRT(svrName):    
    domainRuntime()    
    slrBean = cmo.lookupServerLifecycleRuntime(svrName)    
    return slcBean

But when I run it I got the following error:

     [java] Unexpected error:  exceptions.AttributeError
     [java]  
     [java] Problem invoking WLST - Traceback (innermost last):
     [java]   File
"/products/software/terraferma/release3/EventBus/scripts/admin.py",
line 706, in ?
     [java]   File
"/products/software/terraferma/release3/EventBus/scripts/admin.py",
line 160, in admin
     [java]   File
"/products/software/terraferma/release3/EventBus/scripts/admin.py",
line 455, in monitorServerState
     [java]   File
"/products/software/terraferma/release3/EventBus/scripts/admin.py",
line 473, in getSLCRT
     [java] AttributeError: lookupServerLifecycleRuntime

Where line 473  in getSLCRT is:

    slrBean = cmo.lookupServerLifecycleRuntime(svrName)    

Could anyone help me to understand why ?

Regards