Pnotify don't works in xpages : error javascript

Question

I tried to call the pnotify with a button.

When I clic and if there isn't message, then a message (pnotify) arrives with success and the same with error int the other case.

 <xp:div id="divMessages">  
<xp:messages id="messagesValidation" styleClass=" customErreurSaisie customErreur">
    </xp:messages>              
</xp:div>   

<xp:button id="btnEnregistrer">
            <xp:eventHandler event="onclick" submit="true"  refreshMode="partial" refreshId="divMessages">
<xp:this.action>
                    <xp:actionGroup>
                        <xp:saveDocument var="dsdModeleDeMasque">
                        </xp:saveDocument>
                    </xp:actionGroup>
                </xp:this.action>               
<xp:this.onComplete><![CDATA[


                    var messages = XSP.getElementById("#{id:messagesValidation}");
                    if (messages) {
                                                notifyLastAction("Document non sauvegardé", "essai", "error");
                    } else  {

                        notifyLastAction("Document sauvegardé", "essai", "success");
                    }
                    var proprietes = XSP.partialRefreshGet("#{id:lesProprietes}");
                    if (proprietes) 
                    {
                        XSP.partialRefreshGet("#{id:lesProprietes}");
                    }
                ]]></xp:this.onComplete>
                            </xp:eventHandler>
</xp:button>

My error in the console is TypeError: "Impossible to get the property "destroy" with null or undefined reference ".

Could you help me ?