javascript mouseover image displays the original image and the original image disappears after the mouse is removed (multiple images)_Image special effects

The specific usage is as follows:
Place the Javascript code before (Placing the script code at the bottom of the page will help improve page speed, but I have not yet experienced it personally)

The following is the HTML code:

The above code does not control the position where the original image appears. If it involves If you go to a position close to the edge of the window, you will use attributes such as offsetLeft.
If you think about it carefully, this is actually quite simple. Those who write Javascript need to pay a lot of attention to details. This is really important. If you are not careful, you will make mistakes. The worst thing is that you don't know where the mistakes are.