var usrName = session.findById("wnd[0]/usr/txtPersonas_1452796008773").text="USER01";
var rfc=session.createRFC("BAPI_USER_GET_DETAIL","");
rfc.requestResults(JSON.stringify(["ADDRESS","RETURN"]));
rfc.send();
session.utils.log("FIRST STEP");
var address=JSON.parse(rfc.getResult("ADDRESS"));
session.utils.log("second STEP");
session.findById("wnd[0]/usr/lblPersonas_1453926916445").text=ADDRESS.FULLNAME;