Header () page jump problem in PHP CI framework

Use the header function to jump to find the specified URL can also find the page, but the page is not jump, the URL is not changed, this is how the matter
Request Url:http://localhost/login
Request Method:post
Status code:302
Request Headersview Source
accept:*/*
Accept-encoding:gzip,deflate,sdch
accept-language:zh-cn,zh;q=0.8
Connection:keep-alive
content-length:67
content-type:application/x-www-form-urlencoded
cookie:phpsessid=2k3ap23pdn68ecls5a1kgb8431
Host:localhost
Origin:http://localhost
referer:http://localhost/
user-agent:mozilla/5.0 (Windows NT 6.1) applewebkit/537.36 (khtml, like Gecko) chrome/29.0.1547.66 safari/537.36
X-requested-with:xmlhttprequest
Form Dataview sourceview URL encoded
Username:123
password:e10adc3949ba59abbe56e057f20f883e
Role:student
This is the beginning of the original page

Request Url:http://localhost/student/index
Request Method:get
Status code:200 OK
Request Headersview Source
accept:*/*
Accept-encoding:gzip,deflate,sdch
accept-language:zh-cn,zh;q=0.8
Connection:keep-alive
cookie:phpsessid=2k3ap23pdn68ecls5a1kgb8431
Host:localhost
referer:http://localhost/
user-agent:mozilla/5.0 (Windows NT 6.1) applewebkit/537.36 (khtml, like Gecko) chrome/29.0.1547.66 safari/537.36
X-requested-with:xmlhttprequest
Response Headersview Source
Connection:keep-alive
content-length:856
Content-type:text/html
Date:mon, 14:22:30 GMT
Keep-alive:timeout=5, max=99
server:apache/2.4.4 (WIN32) php/5.4.16
x-powered-by:php/5.4.16
This is the page to jump to