html5 interact communication tools

Json type for websocket:

ErrorMessage : errors from the server errorWord

AlertMessage : some alert alertWord

doodleTable : the doodle function from the user drawElement index

doodlePic : the pic of canvas from a user data to -- the user name of the pic sending to

requestPic : when a new user enter the room, the server send this message to a user to request the pci of canvas from -- the user name of the requesting from

SaveTableDoodle : save the current doodle of table

drageMessage : message about drag movement : begin or stop or move or save