【现场照片】有关技术问题征集电脑高手

我在有关论坛，照片利用鼠标中间键能放大缩小，它的原代码如下：
此主题相关图片如下：<br><A HREF="UploadFile/2005-10/200510250230796.jpg" TARGET=_blank id="ImgSpan"><img SRC="UploadFile/2005-10/200510250230796.jpg" border=0 alt=按此在新窗口浏览图片 onmousewheel="return bbimg(this)" "javascri pt:if(this.width>screen.width-500)this.style.width=screen.width-500;"></A><br><br><img SRC="skins/default/filetype/jpg.gif" border=0 onmousewheel="return bbimg(this)" "javascri pt:if(this.width>screen.width-500)this.style.width=screen.width-500;">此主题相关图片如下：<br><A HREF="UploadFile/2005-10/2005102502317753.jpg" TARGET=_blank id="ImgSpan"><img SRC="UploadFile/2005-10/2005102502317753.jpg" border=0 alt=按此在新窗口浏览图片 onmousewheel="return bbimg(this)" "javascri pt:if(this.width>screen.width-500)this.style.width=screen.width-500;"></A><br><br><img SRC="skins/default/filetype/jpg.gif" border=0 onmousewheel="return bbimg(this)" "javascri pt:if(this.width>screen.width-500)this.style.width=screen.width-500;">

网易暖通论坛，照片利用鼠标中间键不能放大缩小，它的原代码如下：
<a href="http://codata.163.com/upload/forum/89/1129767586125.gif" target=_blank>
<img border="0" src="http://codata.163.com/upload/forum/89/1129767586125.gif" alt=按此在新窗口浏览图片 "javascri pt:if(this.width>screen.width-333)this.style.width=screen.width-333;">
</a>