<html><head><script type="text/javascript" src="/jquery/jquery.js"></script><script type="text/javascript">$(document).ready(function(){ $("button").click(function(){ alert("Image width " + $("img").attr("width")); });});</script></head><body><img src="/i/eg_smile.gif" width="128" height="128" /><br /><button>返回图像的宽度</button></body></html>