Addin url paramater to current page(header location)

Question

Instead of making few header location like:

 header("Location: pagename.php?alert=xxxx");

I want to add ?alert=xxx to current opened page, how to do it?

Answer 1

Try with PHP_SELF

if(!isset($_REQUEST['alert']){
    header("Location: ".{$_SERVER['PHP_SELF']}."?alert=xxxx");
}