Update Subform record into another form

Update Subform record into another form

Hello All,
I am trying to update the subform record into another form

Following is the code i have used:
for each  rec in Accessories_Inward
{
fetRecFrom = Stock[Record_ID == Record_ID];
fetRecFrom.Item_No=rec.Item_No;
fetRecFrom.Quantity=rec.Quantity;
}

whereas,
Record_ID = Unique Identification code to recognize the rec i want to update
Accessories_Inward = Subform of the Main form (not linked with any other form)
Stock = Form where record is to be updated.

Now the Problem is
When there are multiple records inside subform it only updates the 1st rec.
for eg:      Item_No            Quantity
                  Carton                  1500
                  Putty                     2000
Above data is single entry using subform...
When i try to update "Carton" it is getting updated perfectly the way i want but when i try to update "Putty" it doesn't work.

Please refer the Screenshots.
Thank You for Help.