<html><head><script type="text/javascript" src="/jquery/jquery.js"></script><script type="text/javascript">$(document).ready(function(){ $("button").click(function(){ $(":text").val("Hello Kitty"); });});</script></head><body><p>Name: <input type="text" name="user" value="Hello World" /></p><button>改变文本域的值</button></body></html>