Simplest way to test for success/failure of updateRecord?

Simplest way to test for success/failure of updateRecord?

Hi

I am wanting to check the response to an updateRecord call in a custom function invoked by a button to signal success or failure.

update = zoho.crm.updateRecord("Forms",recID,updateData);
if (?????????)
  return "Success";
else
  return "Failure";

What is the simplest way to achieve the ????????.

Thanks