If you add a progress bar to your form it will add code like:
WADFP_SetProgressToForm('form11', 'form11_ProgressMessageWrapper', WADFP_Theme_Options['Bar:CaboSunset']);
Along with other code. I've attached an updated version of: jquery-blockui-formprocessing.js
It will make it easier to open the progress indicator without submitting the form. It includes a function: WADFP_Show_Progress()
You can use that function with the same arguments to open the progress indicator without submitting the form like:
<select onchange="WADFP_Show_Progress( 'form11_ProgressMessageWrapper', WADFP_Theme_Options['Bar:CaboSunset'])" ...
Use the same settings as you have in the WADFP_SetProgressToForm() function just skip the first one (form id) since it isn't attached to the form submit.
Then, to close the progress indicator just use: WADFP_jQuery.unblockUI();
If you re-install the latest DataBridge, it will include the new jquery-blockui-formprocessing.js file in future applications.