使用onclick事件停止并启动幻灯片放映

I want to control this slideshow to start/stop using onclick on #mainImage. At this point, I can get the slides to stop, but I'm stuck on the logic for how to use onclick to start it again. Ideally, I want the slideshow to continue from the array position where it left off as opposed to starting over completely. My instinct tells me this could be solved with some conditional statements, but I just can't get it to work. Thanks for any feedback!I want to control this slideshow to start/stop