17. The computer system of claim 12 , wherein the value in the read-back value is derived from the value entered into the first element using a formula that references the first element.
17. The computer system of claim 12 , wherein the value in the read-back value is derived from the value entered into the first element using a formula that references the first element. 18. The computer system of claim 17 , wherein the formula is a formula in the second element.