How to get the correct element code
This calculation always begins from 0, so first page is p0 and first element on a given page is e0. So for example fourth element on third page would be p2e3. You must count every element, also image and text elements. More information here.
1. Open your survey and go into Build-view and click Settings
2. On the window that opens click 'Snippets' and insert your code into the 'Body bottom:' text box.
jQuery is available for the snippets. It's a good practice to put your script inside a ready handler to ensure that the document has fully loaded before the script is run.
//Your code here