Thank you for your help.
The petname input box is on a page with other elements
This page has in the header:
<!-- include jQuery library -->
So, the JQuery.Ajax() code is in an external myjs.js file (which contains other js as well).
When I execute this webpage, Firebug shows the following:
petnamevalue: ReferenceError: petnamevalue is not defined.
shows the correct input value.
It appears that when I click the button...nothing happens, the JQuery does not fire and petnamevalue does not become defined ??
Thank you for your time on this one.