How to get get and Set the Party list in Javascript:

To retrieve values by jscript: 

var partylistItem = new Array;
//get the items/values in a field named"resources"

partylistItem  = Xrm.Page.getAttribute("resources").getValue();

To set values by  jscript :
To set  values we also  need to  get an  array.
 var partlistset= new Array();
partlistset[0] = new Object();
partlistset[0].id = id; // provide a guid type value
partlistset[0].name = name; // provide a suitable name
partlistset[0].entityType = entityType; // provide the entity  name  of the item  ie account/ contact etc .
Xrm.Page.getAttribute("resource").setValue(partlistset);