The product short decription text area in my version has an ID of "descr".
Assuming your code above is good, I think you would need:
$("#descr").val(result.exampleMes sage);
When adding javascript to smarty tmeplates, you need to wrap it with {literal}
{/literal}
tags on either side.
It might be best for you to hire a developer to do this for you, if you do not understand how to go further with these examples. It will save you time, and time is money.
