workingCopy.getValue attribute in javascript plugin

Hello everybody,
     In the article, https://jazz.net/library/article/782/ , the following source code is used:
this._currentPArea = new String(this.workingCopy.getValue({ path: "attributes.projectArea.id"}));

I wish to use the same syntax to get the value of my own attribut. For example I have the ID,com.ibm.team.workitem.attribute.myattribute, for the attribut:myattribute (string or enumeration type)
Could you tell me if someone have already used it ?
If yes, do you have a code source example ?

I have tried:
var myvar=this.workingCopy.getValue({path: "attributes.com.ibm.team.workitem.attribute.myattribut"}).
When I want to display variable myvar, I get "[Object object]". I don't know what kind of object I have got.
Is it the good way to use this method to get the value of attribut in a javascript plugin ?


Thank in advance for your help.

Best regards
.