关于交换图片的问题

Question

我来捡点分!
<img src="1.gif" onmouseover="this.src='2.gif'" onmouseout="this.src='1.gif'">

Answer 1

<img src=url1 onmouseover="this.src='url2'"  onmouseout="this.src='url1'"></img>

Answer 2

<img src="before.gif" onmouseover="after.gif" onmouseout="before.gif">楼上那头猪，IMG有关闭的标签吗？
 IMG是单标签啊~~~

Answer 3

<img src="before.gif" onmouseover="this.src='after.gif'" onmouseout="this.src='before.gif'">
 不好意思，搞错了