Hi,
Record owners:
Xrm.WebApi.retrieveRecord("account", "d8862a8c-90fe-eb11-94ef-002248800dd0", "?$select=name,_ownerid_value")
.then(function(result) {
var account = {
"accountname": result["name"],
"ownerid" : result["_ownerid_value"],
"owneridtype" : result["_ownerid_value@Microsoft.Dynamics.CRM.lookuplogicalname"]
}
console.log(account);
})

The Customer field:
Xrm.WebApi.retrieveRecord("opportunity", "1d2e438e-1621-4b0e-ae9a-529e06b16d0e")
.then(function(result) {
var opportunity = {
"opportunityName": result["name"],
"customerid" : result["_customerid_value"],
"customeridname": result["_customerid_value@OData.Community.Display.V1.FormattedValue"],
"customeridtype": result["_customerid_value@Microsoft.Dynamics.CRM.lookuplogicalname"]
}
console.log(opportunity);
})
