Hello,
I've one registration page where the users fills in their information, is it possible to trasnfer the things the fill in on the registration page to another script that does someting and returnes something to the first page like true/false and then the registration gives an error messange if the other php script returned false?

Something like the script "activates" another script that does something and returnes the result back to the original script.

Best Regards

Could you use a class? I'm not very experienced with classes in PHP, but would this work for your purposes?

(your first script)
(helperclass.php)

Sounds like you're talking about a form that submits to itself. Basically, the values will be captured by using the $_POST['formElementName'] and then you check to see if the form has been submitted already with if ($_SERVER['REQUEST_METHOD'] == "POST"). If it hasn't been submitted yet, you display the form, if it has you display something else.

i think that registering a session variables is easier, you can save the entered data from the user into a session variable then in any page you should write:

then all the session variable will be defined.

I would suggest simply including (via 'include()') the script from wherever the form is sending its data ('action="page"'), as has more or less already been mentioned.

Depending on the method you instruct the form to use - ie. POST or GET - data entered in the form will be stored in either the $_POST or $_GET arrays respectively once it is submitted. So if you were to include() your script from the page that receives the data, the two abovementioned variables would be accessible.

$_post and $_get recieves the data entered in the last page which contains the form, but what do you have to do if you need it later?!
i think using $_session is better?

Using sessions is not always an option. Nor is it always desired. I try to avoid using cookie or session data wherever I can, and only ever do so if there is absolutely no other option.

PHP often appends the session ID to URLs where it has no other option for 'remembering' the session owner, meaning a link to, say, '/file.php' may become '/file.php?PHPSESSID=(some 32 byte MD5 hashed string)'. This is not only problematic when someone bookmarks or links to a certain page on your website, inadvertedly including the session ID, but also when search engines attempt to crawl your site. I seem to vaguely remember Google advising against the usage of sessions where possible due to the latter reason.

If you need to use data later, I would suggest storing it in a database (even a flatfile will do the trick where no other option is available). Remember that any files include()ed will have access to all variables declared on a global scope (such as $_POST), meaning that if the form submits data to 'page.php', and 'page.php' references 'script.php' via include() or require(), script.php will be able to access and manipulate the data received. If the information is not 'valuable' (for lack fo a better word) enough to store in a database, then you probably don't need to remember it outside of immediate processing anyway.

How to transfer variable from one page to another in php?
Transfer Variables To Another Php Script

I am going to make a login page. After my login I want to print username in in another page. How will I do?

-Imtiaz Alam Khan

well as mentioned above you can use $_POST or $_GET or $_SESSION or $_COOKIE but each method has its pros and cons for example cookies can be created by the user manually and so can infiltrate your system