<a href=\"test.php?id=1\">

[yllai]

<a href=\"test.php?id=1\">

any one can explain to me what this script work? how it pass value id=1 to next page (test.php)?
i noted that some link is as <a href=\"test.php&Submit=yes\">

what is the different between? and & in a link?

where can i get any related information?

[jatar_k]

? is used to say "this is the beginning of the query string"
& is used to seperate the diferent name/value pairs in the query string

[Zipper]

<a href=\"test.php&Submit=yes\"> is not a valid link.
As jatar_k said, you need to add a '?' to begin a query string. so if the query string has id=1 you can get this value using $_GET['id'] in the test.php page.