Xrm.Utility.openEntityForm was introduced in new scripting reference from Microsoft.

It has few variants and I only found few blogs for a complete reference for it. Adding my findings here (Reference from MSDN site):

Open a new account record

JavaScript

Xrm.Utility.openEntityForm(“account”);

Open an existing account record

JavaScript

Xrm.Utility.openEntityForm(“account”,”A85C0252-DF8B-E111-997C-00155D8A8410″);

Open a new account record with a specific form and setting default values

JavaScript

var parameters = {};

parameters[“formid”] = “b053a39a-041a-4356-acef-ddf00182762b”;

parameters[“name”] = “Test”;

parameters[“telephone1”] = “(425) 555-1234”;

Xrm.Utility.openEntityForm(“account”, null, parameters);

Now some pointers on few things it can not do:

· Open a new record with setting form values for regardingobjectid will not work. So, in that case, the Workaround? Here we go:

Open Form Script

//set the parameters to pass to the new form
var parameters = {};
var Regarding = Xrm.Page.getAttribute(“regardingobjectid”).getValue();
parameters[“parameter_regardingid”] = Regarding[0].id;
parameters[“parameter_regardingname”] = Regarding[0].name;
parameters[“parameter_regardingtype”] = Regarding[0].entityType;
//Open the new form
Xrm.Utility.openEntityForm(“appointment”,null,parameters);

onLoad Script for new form which needs to be opened:

// Get the Value of the Regarding through the Customer Parameters
var param=Xrm.Page.context.getQueryStringParameters();
var regardingId=param[“parameter_regardingid”];
var regardingName=param[“parameter_regardingname”];
var regardingType=param[“parameter_regardingtype”];
//Populate the Regarding if there is one
if (regardingId != undefined)
  {Xrm.Page.getAttribute(“regardingobjectid”).setValue([{id:regardingId, name:regardingName, entityType:regardingType}]);}  

· In some cases, it might not work for Lookup attributes on custom entities, there is no official documentation, but an approach similar to one mentioned above will work.

Hope it helps!