Testimonial widget- next button

Hi there,
I’m trying to put next button to my the Testimonial widget on the home page.
I followed the following post:
http://ww.wp.xz.cn/support/topic/plugin-testimonials-widget-next-testimonial-not-pagination?replies=4

I added the script to the footer (just before the </body>) and the HTML element with the class “next-testimonial”. I changed the the function name to “nextTestimonial2()” according to my source code.

Unfortunately it didn’t work.
I’m new to WordPress so I would appreciate your help.
Thanks in advance!

http://ww.wp.xz.cn/plugins/testimonials-widget/