Purchase order change, when you run the query, but the contents of the order slip that you entered in the past will be the initial display, it is necessarily as it is not ordering documents that were saved in the most recently is displayed. So, do you order document, which is the initial display has been determined how. This time, explains the initial display of the mechanism of the order slip.
Screen transaction SAP is has become mechanism value processed most recently for each parameter ID specified in the screen item is stored in the SAP memory is initially displayed on the item with the same parameter ID screen transactions performed since you. However, the order registration (Tr-Cd: ME21N), Order Change (Tr-Cd: ME22N), order inquiry (Tr-Cd: ME23N) 3 single transaction is implemented from the R / 3 version 4.6 called "the Enjoy" in screen transaction of the new design, the traditional screen transaction depends on the initial display of the mechanism. While actual execution of the transaction, I would like to try to explain the initial display of the mechanism of ordering Enjoy screen.
First, purchase order registration (Tr-Cd: ME21N) to save the order slip in. In this example, it has been stored in the order number 4500000049. 
When the document is saved, the value you enter will be clear once all. 
Then, run the purchase order change. To move from the order registration screen to the order change screen, the previous screen (horizontal arrow) on the screen, the end (up arrow), to close the order registration screen by pressing one of the buttons of discontinuation (crosses), SAP menu or enter the order change screen from, 
ordering change transaction code of (Tr-Cd: ME22N) There are two ways to enter the order change screen by entering into direct the. 
Previous screen, Exit, to close the order registration screen by pressing one of the buttons of the stop button, ESDUS: was saved with the user name in a table called "inventory / purchasing management dynamic user configuration" order number will be updated. 
When you enter from the SAP menu to order change screen, ordering data of the order number that has been updated in the table ESUDU will be initially displayed. In this example, the data of the order number 4500000049 registered immediately before is initially displayed. 
Select the menu "Purchase Order" → "other purchase order", it calls the data of another order document 4500000045. 
Display of the order data has been switched. 
Then, without changing the order data, you try to close an order change screen by pressing a button on the screen.
Regardless of the presence or absence of the document storage, (in this example, 4500000045) slip number of orders data displayed on the most recent in a table ESDUS will be updated.
Once again the order change screen from the SAP menu, ordering data of 4500000045 that has been updated in the table ESDUS will be initially displayed. 
In, call the data of the order slip 4500000049, which was first registered by selecting the menu again "other purchase order". 
Display of the order data has been switched. 
This time, specify the transaction code ME22N, you re-enter the order change screen.
Then, most recently instead of 4500000049 was displayed, ordering data of 4500000045, which was displayed in the front has been the initial display. 
When I query the table ESDUS, we remain of 4500000045 by order number 4500000049 was displayed in the most recent is not updated. 
In other words, in order "Enjoy" screen transaction, full-screen on the screen, the end, only when you exit the screen by pressing one of the buttons of discontinuation, order slip that has been displayed in the immediate vicinity regardless of the saving presence or absence of data number is stored in the table ESDUS, it the order data in the next screen transaction has become a mechanism that is initially displayed.
Once you get used to the SAP of operation orders, enter the transaction code rather than from the SAP menu, but is prone to perform the following screen transaction, and carried out in such order the operation "Enjoy" screen, we were treated to the most recent no document number is stored, when you open an order change or query screen, the past of the order data that is not familiar is the initial display, there is a possibility that the input mistake unexpected. By understanding the order "Enjoy" screen transaction mechanisms, please go to the appropriate screen operation.