Add text to field loaded from external JS

Add text to field loaded from external JS

I'm trying to add text to a textarea on a form using jQuery. The form
loads via JS from an external site.
Fiddle Here
The textarea is the 'When would you like a demo?' field. I believe it is
this field.
<textarea name="Demo" class="k_textarea k_required" id="Question_1"/>
I've tried referencing the field directly by ID (see fiddle) and used a
delay in case this was a resource loading order issue. Suggestions?