Duplicate forms-prevention on use of date of birth+ surname

The reply to my query ( prav_123)is basically the help I need very much: I
don't have a 'student number' in my form field and I tried to substitute Date
of birth in the sample code sent.I am a real novice but 'nothing happened!
just got duplicate form entries.How do I link the code to my datatable/forms
for it to work.There will be a risk of more than one person sharing the same
date of birth but this risk is small for my needs.If I could include the
individual's surname how do I state both these parameters in the code.Please
help/Many thanks

When you don't have a natural unique identifier, the best option is to use
an autonumber. What would you do if you had two people with the same
surname and date of birth? Would you change their surname? Would you
change their date of birth? Would you change the application to add a
sequence number to the primary key?

"prav_123" wrote in message
...
The reply to my query ( prav_123)is basically the help I need very much: I
don't have a 'student number' in my form field and I tried to substitute
Date
of birth in the sample code sent.I am a real novice but 'nothing happened!
just got duplicate form entries.How do I link the code to my
datatable/forms
for it to work.There will be a risk of more than one person sharing the
same
date of birth but this risk is small for my needs.If I could include the
individual's surname how do I state both these parameters in the
code.Please
help/Many thanks