Hi,

please, is possible to generate a script that runs at change field?

For example if I write "text" in any field in other field writes "You have written text"

Thanks,

Look into the OnObjectSave script trigger. This will trigger a script when you change and try to save the contents of a field on a layout. One caveat to keep in mind is that the trigger applies to a field object on a layout, not the underlying field itself; so it will only apply to one field object on a layout. Changes to the same field in a different field object without the trigger applied will not trigger the same script (or any script, for that matter).

is possible to generate a script that runs at change field?

I am guessing by "change" you mean "modify"? If so, you should look into running the script OnObjectModify. However, the OnObjectValidate and OnObjectSave triggers are possible choices, too - all depends on what exactly you're trying to achieve.

For example if I write "text" in any field in other field writes "You have written text"

What would be the purpose of that?