Hi Poornima,
To achieve your requirement you can display the list of deliveries (In the same screen or different screen) and you can create page up and page down button and a pushbutton.The user can go through the list of deliveries and then he can select one and click on the pushbutton to confirm his selection. This will save the user selection and the same selection which is captured can be used for processing in your code.
Regards,
Vivian