This is the entry grid used through out the system.

The Drop down button allow user to drop down a list of selection items, user may direct key in the field to auto search for items in the drop down list without having to drop down the menu.

Menu dropped down.

The button will link to any source screen, in this example, account setup screen will be activated if click.

Auto Calculate Field

Total Amount will never need any key in or changes, all changes to the U.Price / Qty/ Dc(%) will be auto calculated.