Feeling hurt by TeleBears? Fine, we've designed a new enroll/drop system to stop your tears! The system works like a gambling game. Every student has a certain amount of tokens(default to 1000) and he/she has to make a bid for every course. The sum  of his/her bids cannot exceed 1000. After everyone has  made bids for  the courses, the system  will automatically enroll students  for each course.  For each course, we  basically choose the students  who make the  highest bids(if  two students make  the same bid, first  come first  enrolled). However,  students can  check whether his/her bids ensure enrollment and drop  class or change bids as long as he/she logs in again.