when I use this:
require(\"diggstyle_code.php?page=$page_no\");
the warning is :failed to open stream: No error in C:\\xampp\\htdocs\\4ajax\\ga
require, require_once, include and include_once try to include files from the filesystem in the current file.
Since there's no files named diggstyle_code.php?page=1, it's totally logical that PHP can't find it.
You can't pass values that way, however, any variable declared in the current file will be accessible in the included files.