How do I write a macro to automatically fill in the next number in a sequence

[Barbara]

I have a database with existing information and need to create and want to add a new number in an existing sequence when and new Purchase Order Number is added. I know I need a macro but I do not know how to write it. Can someone please help? Thanks so much.....

[Bob Fitz]

You could set the Default Value property of the textbox to
=DMax("YourPurchOrdNumField","YourPurchOrdTableName")+1
I think this would work for a single user app, but you could have problems in a split db with multiple front ends.