PHP代码在本地工作，但不在服务器上

I asked this a while back but it was regarding other things.

On my local server, if i go to www.localhost/en/register/ i have a form. Once i submit the form, it doesn't submit to the page. The page doesnt seem to read it or something.

Here is the form:

<form class="form_main" method="post" action="/en/register/">
            <h2>Registration</h2>
                <table>
                    <tr><td><label>Username</label><input maxlength="15" type="text" name="username"></td></tr>
                    <tr><td><label>Password</label><input maxlength="32" type="password" name="password"></td></tr>
                    <tr><td><label>E-Mail</label><input maxlength="50" type="email" name="email"></td></tr>
                    <tr><td><label>How did you find us?</label><input maxlength="50" type="text" name="howfind"></td></tr>
                    <tr><td><label>Why do you want to join?</label><textarea maxlength="1000" rows="5" cols="30" type="text" name="join"></textarea></td></tr>
                    <tr><td><input class="button_o" value="Send" type="submit"></td></tr>
                </table>
            </form>

On local, it works perfect but on my server, it doesnt seem to read my code.

if(isset($_POST['username'],$_POST['password'],$_POST['email'],$_POST['howfind'],$_POST['join'])){
//Some code here
}

I noticed that none of my forms works. It doesnt submit the things when i click submit. It just reloads the page it looks like. Does anyone know why?

Yes, i have a <base href=""> if anyone asks.

EDIT: After removing the action attribute, it seem to work but as soon as i do something like if(empty($_POST['something'])){} it makes the page white without errors.

Verify if the action of your form is sending the post data to a url that gets redirected as http status 301 or 302. If so, this may be the problem. To make this check, open Firebug in Firefox or Chrome developer tools, go to the "network" tab, and click on submit in your form. You should see your post request along with its http status. You may also see the posted data. But remember, post will only be available if the http status is 200.

Maybe your server is redirecting urls thats finishes with slashes ("/") to a url without slashes, and this may be causing the 301 http status. Try to remove the slashes of your urls in the action of the form.