Hi Golden,
These are the changes I made:
1) Added an input parameter StockName with Data Type text to UpdateStockQty, and assigned it to the StockName attribute of the retreived entity record. (btw. maybe a good idea to change the name of the server action to UpdateStockRecor)

2) In screen action StockRowSave I added the current record StockName parameter to the call of UpdateStockQty

The attached module has the changes.
Regards,
Daniel