in my organization we using an biometric device for attendance entry (essl-model number-x990) in that data comes through network to computer . at computer I'm using sql data base sql server 2008 in that table is there whch indicates userid logdate&time checkin/out, the problem is in that database table I was unable to define if an user punch his finger print second time it automatically consider as "check out" due to this non configuration my table is showing all the log time in&out showing as check in how to design this?