触发图像特定部分的事件

I want to trigger an event handler when the user hovers on a particular part of the image, like the center of the image or the right side of the image (area would include, say, about a 100 pixels). I am not using any framework, so this is normal javascript that I am working with. I am not sure if using image maps would work. Can anyone help?I want to trigger an event handler when the use