Zoom 
or 
Click the Zoom button ()
or press F9 to open a detail form associated with particular data entry
fields, such as customer bill-to and ship-to addresses, and item serial
numbers or shipping instructions.
The detail form that opens allows you to view or edit existing details or add new details. You then click the F9 key to close the detail form.
When you're in a detail form that also has a Zoom button beside a field, you must press Shift + F9 to see another detail form specifically for that field; if you simply press F9 again, the detail form closes. (This function is referred to as Detail Zoom; you again press Shift + F9 to close the second detail form.)