How should I enter a value in a field automatically when I fill another field in the same form

Hi,

I have a problem when I try to enter a value in a form. What I want is to modify the General Journal form. At the moment when I enter a value at Applies-to Doc. No. , I want the External Document No. to be filled automatically with the same value that I entered in the Applies-to Doc. No. field. I tried entering this code in the OnValidate trigger of Gen. Journal Line table

VALIDATE(“External Document No.”,“Applies-to Doc. No.”); but it did not work. Can anyone help me?

Thanks a lot.

Where did you place that code?

I placed the code in Applies-to Doc. No.- OnValidate

Thank u.

Most of the time when I do something like your talking about you need to do it in the table design.