The "Value Labels" dialog box has three main fields. 
The first, labeled "value," is where you can type in the numeric value which you wish to define.
The second, labeled "value label," is where you can type in the label for the numeric value.
The third field contains a list of all the values you have already defined.

To add a new value label, type the number in the first box, hit Tab, 
type the value label in the second box, hit Tab, then Enter.
To save your changes, hit Tab three times or until the pointer is over the button OK, then hit Enter.