fixed up the null cases to be more descriptive
Merge pull request #9 from hongyi192/master

fixed up the null cases to be more descriptive
Change helpString string
Fixed a usability issue with infoses
Merge branch 'master' of https://github.com/DavisWang/uwcr-chatbot
Merge branch 'master' of https://github.com/DavisWang/uwcr-chatbot
ready for pull request