import value from an textbox if no value here.

[Zerdax]

HI,
Is it possible to import an value from an textbox to a textbox bound with an table if there is no value in it.
! import or write ur own value in the textbox

code should be:
Import from [text97] if no value in it.
It should update continously. cus the value that is supposed to import will be calculated when enterd other datas. so it wont import 0 cuz that is the value on start

Any help.