php注册提交可以写到数据库中，但是不能显示注册成功执行不了之后，是哪里不对？的语句
<?php session_start(); header('Content-Type:text/html;charset=gb2312');?><!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><html xmlns="http://www.w3.org/1999/xhtml"><head><meta http-equiv="Content-Type" content="text/html; charset=gb2312" /><title>注册</title><link rel="stylesheet" href="css/style.css" /><script language="javascript" src="js/xmlhttprequest.js"></script><script language="javascript" src="js/register.js"></script><style type="text/css"><!--#Layer1 { position:absolute; left:315px; top:266px; width:349px; height:25px; z-index:1;}--></style></head><body><div id="container"><div id="rgbgdiv"> <div id="regnamediv"><b>注册学号：</b><input id="regname" name="regname" type="text" /><div id="namediv">请输入学号，做为登录账号</div> </div> <div id="sturegrealnamediv"><b>真实姓名：</b><input id="sturealname" name="sturealname" type="text" /><div id="realnamediv">请输入姓名</div> </div> <div id="regpwddiv1"><b>注册密码：</b><input id="regpwd1" name="regpwd1" type="password" /><div id="pwddiv1">请输入密码</div> </div> <div id="regpwddiv2"><b>确认密码：</b><input id="regpwd2" name="regpwd2" type="password" /><div id="pwddiv2">请输入确认密码</div> </div> <div id="sturegsexdiv"><b>学生性别：</b><input id="stusex" name="stusex" type="text" /><div id="sexdiv">请输入性别</div> </div> <div id="sturegquestiondiv"><b>密码问题：</b><input id="stuquestion" name="stuquestion" type="text" /><div id="questiondiv">找回密码时使用</div> </div> <div id="stureganswerdiv"><b>密码答案：</b><input id="stuanswer" name="stuanswer" type="text" /><div id="answerdiv">找回密码时使用</div> </div> <div id="sturegfacultydiv"><b>学生院系：</b><input id="stufaculty" name="stufaculty" type="text" /><div id="facultydiv">请输入你的院系</div> </div> <div id="sturegsubjectdiv"><b>学生专业：</b><input id="stusubject" name="stusubject" type="text" /><div id="subjectdiv">请输入你的专业</div> </div> <div id="sturegclassdiv"><b>学生班级：</b><input id="stuclass" name="stuclass" type="text" /><div id="classdiv">请输入你的班级</div> </div> <div id="sturegenteryeardiv"><b>入学年份：</b><input id="stuenteryear" name="stuenteryear" type="text" /><div id="enteryeardiv">请输入你的入学年份</div> </div> <div id="regemaildiv"><b>电子邮箱：</b><input id="email" name="email" type="text" /><div id="emaildiv">请输入你的电子邮箱</div> </div> <div id="sturegtelephonediv"><b>联系电话：</b><input id="stutelephone" name="stutelephone" type="text" /><div id="telephonediv">用户的联系电话</div> </div> <div id="btndiv2"> <button id="regbtn" disabled="disabled" name="regbtn" onclick="process()"> </button> <button id="logbtn"> </button> </div> <div id="imgdiv" style=" visibility: hidden;"> </div></div></body></html>
echo "<script>alert('注册成功！');window.location.href='login.php';</script>";