press spacebar and bring nothing

Hi all,

In the computer which I am using, I need to type every time the values in any SAP field to be used, for example the Sales order number field.In other computers I used to press the Spacebar or Backspace key on the keyboard to get the latest entry in those fields.This results in wastage of time when we are using the same entries more frequently and have to note these numbers anywhere.

Can anyone help me to enable this option of Spacebar or Backspace?

Allen