I have 3 images. 1.jpg, 2.jpg, 3.jpg. I want to distribute them into three `img` elements randomly (on window refresh, the three images' positions will change).  

How do I use `Math.random()` here? Thanks.

```
<img src='' id='img1' />
<img src='' id='img2' />
<img src='' id='img3' />

```