solving calculations involving Time

Help please..
here are the specs of our program..
we are to create a program that would act as an internet usage tracking system. it's simple, the program would be installed in one PC and would serve as a logbook. Each student is given 200 minutes of internet time per week.
my idea was...
that if i could get the time that they logged-in and the time they logged-out, i could get the difference(log-out minus log-in) to get the number of minutes that they have consumed so that i could subtract that from their total available internet time. the problem is, i don't know how to subtract time. i tried the val(text1.text) - val(text2.text) method but the answer comes out as zero. any suggestions guys? we've only got at least 3wks to do this together with a User's Manual and external documentation. thanks a lot guys!

Just
text1.text *1.0 - text2.text*1.0
or cdate(text1.text)- cdate(text2.text)

But if you want 200 min exactly, if they never got out you will never stop the service, you have to have a process that continuosly is checking if he is on board or not and adding the time in a database where all students status and time is set.

datediff()

how do you use the datediff function?

The entire VB6 reference is online courtesy of MS.

http://msdn.microsoft.com/library/e...fctDateDiff.asp