Copy value from one field to another

Hi,

I have a form with a field name. I want to get the value entered in the filed name get copied to another filed name for bank if a checkbox gets marked.

I tested a lot with triggers, but have no clue how to achieve that? Could you please give me an example?

Thanks a lot!

Markus

Can be closed - it is not necessary any more.

Did you do it with a custom JavaScript code ?