Adding OK button in the Message Box
Adding OK Button -1
Merge branch 'megha'
Merging Ok button into master
removing irrelevant comments
Older versions of php do not have http_response_code
Add work-around to task_fetcher.php
Update documentation for state
Remove greenhouse1 from list of published problems:
There is no description and the problem is *very* complicated.
Fixing broken problems and adding images
Merge branch 'master' into jingxian
Code review for intro video opening in separate window