js jquery 验证写法

<?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>