Adding Table control in standard Transactions

Hello Experts,

I have a requirement for which i need to enhance VA41/VA42/VA43 Transactions , I am using Badi  'BADI_SLS_ITEM_SCR_CUS' for this development.

In Item Level i need to add a table control , i created that table control and storing table control data into a ZTABLE with reference to VBELN using user-exits.

The Issue is when i enter data in table control for a line item(for ex: POSNR = 10),then I add another line item (for ex:- POSNR = 20), the data of first line item copy automatically into second line item, if i refresh table control then it erases all data.

Kindly Suggest the solution...

Thanks & Regards

Sushil Kumar Shrivastava