How do you make the id + 1 ?

Question

Hi expert,

 

I would like to know how do we go about generating a formNo such that when the next user submit a form, it will be 2 instead of 1 ?

 

Basically, this formNo format requirement is like this :

 

ABC + yymm + "-" + id which will be 2 when the user submit form the 2nd time.

 

Tks.