Where do I find the code that gets executed when the submit button of the Application is pressed?  I know it executes document.adminForm.submit(), but could not find the code for the submit().  Where is it?

The "document.adminForm.submit()" is an implied function of the form (i.e. there is no code). If you'd like to execute some code before submitting, you could modify the submit button by making it a regular button that executes a function in javascript and have the script execute the "document.adminForm.submit()". I think that might be what you're getting at.