如果你需要取得上一个screen的值，而不能产生某些ID参数如何操作。（从ittoolbox公司来）。
Q：My requirement is to copy the values of a field from one subscreen to the other when changing the tabs. For example, in PO transaction, when one switches from a tab to another, value from a particular field should be copied into a specified filed. I have tried with using get parameter in the PBO of the second subscreen, but that parameter id is not set in the PAI of the first subscreen. It is not possible to modify the first subscreen logic.
A：The way can be achieved is through Function Module
DYNP_VALUES_READ.
You can use this function to fetch the Values of One Screen when you are
in another Screen.
Pass the Program Name and screen number is the variables dyname(eg.
CRMD_ORDER) and dynumb( eg. screen No 0123).
You need to pass the aa the Screen Variable Names whose value you want to
read in Table dynpfields.
But, the sy structure variables cannot be directly passed to this function,
you need to copy them in a variable and then pass that variable as input for
dyname and dynumb.