Choose different User, when creating a worklog

For pair-programming it would be handy, that both developers are able to track their time in JIRA without the need to logout/login again. Therefore it would be nice to have a userpicker, which is filled with the current username, on the CreateWorklog-Screen. This would increase the probability, that both developers are actually tracking their time.
A nice side-effect would be, that someone can log work by order of someone else.