Set user in People picker control in SharePoint using JavaScript

$(document).ready(function() {


    var url = "/_api/web/GetUserById(" + _spPageContextInfo.userId + ")/";
    var user = "";
    getItems(url, function(Users) {
        user = Users.d.LoginName.split('|')[1];
        if ($("select[title='Status'] option:selected").text() == "Received") {
            $("select[title='Status']").val('Pending');
            window.setTimeout(function() {
                SetAndResolvePeoplePicker('Document Owner', user);
            }, 750);
            var d = new Date();
            y = d.getFullYear();
            m = d.getMonth() + 1;
            day = d.getDate();
            $("input[title='Reviewed Date']").val(m + "/" + day + "/" + y)
        }
    });

    $("select[title='Status']").change(function(e) {
        if ($(this).val() == "Approved"||$(this).val() == "Pending") {
            var d = new Date();
            y = d.getFullYear();
            m = d.getMonth() + 1;
            day = d.getDate();
            $("input[title='Reviewed Date']").val(m + "/" + day + "/" + y)
        } else {
            $("input[title='Reviewed Date']").val("")

        }
    })
});

function SetAndResolvePeoplePicker(fieldName, userAccountName) {

    var controlName = fieldName;

    var peoplePickerDiv = $("[id$='ClientPeoplePicker'][title='" + controlName + "']");

    var peoplePickerEditor = peoplePickerDiv.find("[title='" + controlName + "']");

    var spPeoplePicker = SPClientPeoplePicker.SPClientPeoplePickerDict[peoplePickerDiv[0].id];

    peoplePickerEditor.val(userAccountName);

    spPeoplePicker.AddUnresolvedUserFromEditor(true);

    //disable the field

    //spPeoplePicker.SetEnabledState(true);

    //hide the delete/remove use image from the people picker

    //$('.sp-peoplepicker-delImage').css('display','none');

}