Javascript/Greasemonkey script to copy text fields from tab to tab

Javascript Greasemonkey script to allow name and address text data from several fields to be copied from a web page on one tab in Firefox to another page on a second tab in Firefox. The script should create a button on the first page that says "Copy" and a button on the second page that says "Paste". Here is an example: First tab contains a div or text input with an id of "id_lastname". The copy button will need to copy the data from the input/div's by id. On the second tab the paste button will need to paste the text that was copied from the first page into the input for lastname. The end result is the name and address text will be copied from one tab to the other. The from and to field ID's should be stored at the top of the script and made easily editable to allow future changes. A sample page to copy "TO" or paste to is attached.