Set up a self-relationship for Calvesnumbers by it's Fencenumber field. Then, use an auto-enter calculation for the Calvesnumber = [max ( Calvesnumbers::calvesnumber ) + 1]
This will look at the related records, find the last calvesnumber used for the fencenumber entered, add one, and store it.
I am now one step closer!!
But I really would like the field Calvesnumber to just give me a message, if I am typing a number that already exist in the calvesnumber-field.. Because the calvesnumber can be anything number from 1- 600..
Can you fix that?
Just to make it clear:
Fencenumber 1, for example, can have any cind of number from 1-600. It will not be possible to know what kind of number it will be. It could be 431 or 13 0r any other number.. And if 431 is entered in Fencenumber 1, it must not be entered there anymore. Therefore a message should appear: - that this number is already entered.. The same goes for Fencenumber 2 and so on. Except that Fencenumber 2 can also have the same number 431 and 13, like Fencenumber 1, because it's a hole new series of Fencenumbers...
Hopefully this was understandable
Perfectly clear. There may be a way to setup 'Validation by Calculated', but I tend not to use that option.