I would like to add several customize fields into sals order item. I appended a structure to vbap, then i want to design our own layout for user to input those fields, I use SAPMV45A-4462 (I'm not sure whether is right screen or not). Once I go to change mode, then there have a screen to ask me for acess key. what's the key means? I've already input the key when I first time using se38, and i can modify / create a program. Thanks!