calculate new record value from older records

[rjpeters]

simple db holding cd details.
main form holds cd title etc
subform holds tracks, has fields [TrackNo] & [TrackCount]
when I make new record I want to set TrackNo to previous TrackNo+TrackCount (will worry about validating that does not already exist afterwards)
Should not be hard to do but work it out! (mental block or just mental)
Using Access97.
Any help appreciated
- R. Peters

 

[erezmor]

use DMax function to find the maximum value and add 1 to it.
say the subform is based on a table named CDtracks with fields (cdID,TrackNum,TrackName...) then using
DMax("TrackNum","CDtracks","cdID=" & txtcdID) will return the highest value in TrackNum - to which you can add 1 and assign to the new record
good luck,
Erez.