<?php header("Content-type: text/html; charset=utf-8"); ?> <script src="jquery.min.js"></script> <form action=""> <input type="text" name="user_name"> <span></span> </form> <script> $("input[name=user_name]").focus(function() { $("input[name=user_name]~span").html("请输入4-6位号码"); }).blur(function() { /*这里做一个函数检测*/ $("input[name=user_name]~span").html("输入正解"); }); </script> <script> Javascript 返回上一页: 1. history.go(-1), 返回两个页面: history.go(-2); 2. history.back(). 3. window.history.forward()返回下一页 4. window.history.go(返回第几页,也可以使用访问过的URL) 例: <a href="javascript:history.go(-1);">向上一页</a> response.Write("<script language=javascript>") response.Write("if(!confirm('完成任务?')){history.back();}") response.Write("</script>") response.Write("<script language=javascript>history.go(-1);</script>") <a href="javascript:history.go(-1);">向上一页</a> 页面跳转: P.S. 小技巧(JS引用JS): <script type=text/javascript> <!-- if (typeof SWFObject == "undefined") { document.write('<scr' + 'ipt type="text/javascript" src="/scripts/swfobject-1.5.js"></scr' + 'ipt>');} //--> </script>