Dynamics 365/CRM | Set the value and text of a Lookup field

gistfile1.js

// Set the value and text of a Lookup field

// First, you need the GUID, Name and Entity Type stored as variables
// For this example, let's assume we have a "Parent Customer 2" field 
// on a Contact and we want to populate it with the same value as the
// Parent Customer 

// Get the GUID 
var id = Xrm.Page.data.entity.attributes.get("primarycustomerid").getValue()[0].id;

// Get the Company Name
var name = Xrm.Page.data.entity.attributes.get("primarycustomerid").getValue()[0].name;

// Set the entity type - Account, Contact, Lead, Opportunity, etc. 
var entityType = "Account";

// If the ID isn't null, then create a variable to store the new Object
if (id != null) {
  var lookupVal = new Array();
  lookupVal[0] = new Object();
  lookupVal[0].id = guid;
  lookupVal[0].name = name;
  lookupVal[0].entityType = entityType;
  
  // Set the value of the custom "Parent Customer 2" field
  Xrm.Page.getAttribute("new_parentcustomerid2").setValue(lookupVal);
}