arrays

[kahlinor]

This is NASM? What's with all the comment characters? Or are semicolons used as statement separators here?

I think your problem may be with addressing:

mov dx,[student] ; Load dx with word value at label 'student'

try:
mov dx, student ; Load dx with address of label 'student'

If this doesn't work, 16 bit NASM is not a part of my training, so I can't help further.

You could join the NASM groups in yahoo

http://groups.yahoo.com/group/win32-...guid=164610442
http://groups.yahoo.com/group/linux-...guid=164610442

Although the groups are not focused on DOS, there are users there who are familiar enough with DOS to possibly help you out.