Merge pull request #443 from LI-HE/master

solved the restriction issue in both quest and practice page
Merge pull request #25 from ChrisBoesch/master

update
Update normal_play_page.html
Merge pull request #444 from ruijunhuang2010/master

Merge pull request #25 from ChrisBoesch/master
rectify small bug
Merge pull request #445 from ruijunhuang2010/master

rectify small bug
Merge pull request #30 from ChrisBoesch/master

update