Insert value to sharepoint person or group field using JavaScript

Hi,

How to Insert value into SharePoint Person or Group field using JavaScript?

I've used the below code, but value is not saving in SP List

tempListItem.set_item("AuthorNames", currentListItems.get_item("NewsAuthor").get_lookupId());

//AuthorNames-->Person or Group Field

//NewsAuthor--> Person or Group Field

Thanks, Kaviya (Please remember to click “Mark as Answer” on the post that helps you)