XAMPP Path to include in PHP and AJAX - php

Question

After reading tons of articles and trying out a lot code I coudn't make it work to include a php file form my localhost. And know I cannot even specify a path in javascript code like
xmlhttp.open("GET","/DB/ajax/ajaxDeleteRow.php?q="+commentId,true);
I would like to include the file: drawTableSqlString.php which is in the same folder as my file: CommentTableAndDeleteAjax.php. they are in the folder: C:\xampp\htdocs\DB\ajax
What I tried so far:
1.
echo get_include_path(); and i got displayed: .;C:\xampp\php\PEAR
then I tried to copy my file into that folder --> didn't work.
echo dirname(drawTableSqlString.php);
I got an error:
Notice: Use of undefined constant drawTableSqlString - assumed 'drawTableSqlString' in C:\xampp\htdocs\DB\ajax\CommentTableAndDeleteAjax.php on line 36
3.
after changing path in php.ini from "include_path=".;C:\xampp\htdocs"" to include_path=".;C:\xampp\php\PEAR"
i tried:
include ('\DB\ajax\drawTableSqlString.php');
include ('DB\ajax\drawTableSqlString.php');
gives an error as aways which looks like this:
Warning: include(\DB\ajax\drawTableSqlString.php): failed to open
stream: No such file or directory in
C:\xampp\htdocs\DB\ajax\CommentTableAndDeleteAjax.php on line 33
Warning: include(): Failed opening '\DB\ajax\drawTableSqlString.php'
for inclusion (include_path='.;C:\xampp\htdocs') in
C:\xampp\htdocs\DB\ajax\CommentTableAndDeleteAjax.php on line 33
Based on other forum entries I also tried all that code below but nothing worked:
//************************** include DB connection INFOS
//$xajax_dir = 'C:\\xampp\\htdocs\\DB\\ajax';
//include( $xajax_dir . DIRECTORY_SEPARATOR . 'drawTableSqlString.php' );
//include('./localhost/DB/ajax/CommentTableAndDeleteAjax.php' );
//include('localhost/DB/ajax/CommentTableAndDeleteAjax.php' );
//include('./DB/ajax/CommentTableAndDeleteAjax.php' );
//include('DB/ajax/CommentTableAndDeleteAjax.php' );
//include('C:/xampp/htdocs/localhost/DB/ajax/drawTableSqlString.php' );
//include_path = ('.;C:\xampp\php\PEAR','C:\xampp\htdocs\DB\ajax\drawTableSqlString.php');
//include('127.0.0.1/DB/ajax/CommentTableAndDeleteAjax.php' );
//include('C:\xampp\htdocs\DB\ajax\drawTableSqlString.php');
//FROM http://stackoverflow.com/questions/17003614/including-files-from-include-path-not-working-as-expected
//include_once ('/DB/ajax/drawTableSqlString');
//include_once("C:/xampp/htdocs/DB/ajax/drawTableSqlString.php");
// include __DIR__ . 'drawTableSqlString.php';
// include '../drawTableSqlString.php';
//include('http://127.0.0.1/DB/ajax/CommentTableAndDeleteAjax.php' );
//$xajax_dir = 'C:\\xampp\\htdocs\\DB\\ajax';
//include( $xajax_dir . DIRECTORY_SEPARATOR . 'drawTableSqlString.php' );
//include ('drawTableSqlString.php');
//include_path=".;c:\php\includes"
//http://www.php.net/manual/en/ini.core.php#ini.include-path
//set_include_path(".;c:\xampp\htdocs\DB\ajax");
//include ('drawTableSqlString.php');
//echo get_include_path();
Any help would be really apreciated.
EDIT:
Since I changed some parts of the php.ini I get an error when staring XAMPP saying:
Fatal Error: Directive 'register_globals' is no longer available in
PHP