I have the following js function, which makes an ajax request, but it is not doing it for some reason. I checked alerting url and it displays it as it supposed to be, so all variables are declared.

var request = new XMLHttpRequest();

var url = ajax_js/q_ajax.php?q=+ques+

                            &ans=+ans+

                            &a=+inp[0].value+

                            &b=+inp[2].value+

                            &c=+inp[4].value+

                            &d=+inp[6].value+

                            &cor=+checked+

                            &def=+input+

                            &q_n=+q_name+

                            &c_id=+c_id;

request.onreadystatechange=function (){

    if(request.readyState==4 && request.status==200){

        alert(request.responseText);

    }

    request.open(GET, url, true);

    request.send();

}

Here is the code from php file.

<?php

require(db_conx.php);

$q = $_GET['q'];

$ans = $_GET['ans'];

$a = $_GET['a'];

$b = $_GET['b'];

$c = $_GET['c'];

$d = $_GET['d'];

$cor = $_GET['cor'];

$def = $_GET['def'];

$q_n = $_GET['q_n'];

$c_id = $_GET['c_id'];





$q = mysqli_escape_string($con, $q);

$ans = mysqli_escape_string($con, $ans);

$a = mysqli_escape_string($con, $a);

$b = mysqli_escape_string($con, $b);

$c = mysqli_escape_string($con, $c);

$d = mysqli_escape_string($con, $d);

$cor = mysqli_escape_string($con, $cor);

$def = mysqli_escape_string($con, $def);

$q_n = mysqli_escape_string($con, $q_n);

$c_id = mysqli_escape_string($con, $c_id);





/* Modify id for the system  */

$query = mysqli_query($con, INSERT INTO course_quiz (course_id, quiz_name, question, des_answer, ChoiceA,

                                                      ChoiceB, ChoiceC, ChoiceD, correct, def)

                            VALUES ('$c_id', '$q_n', '$q', '$ans', '$a', '$b', '$c', '$d', '$cor', '$def'));

echo('Question has been saved');

/* header('Location: ../instr_home.php'); */

I also have an another ajax call(works perfect) in the same page, which I think the reason of the problem. Variables for XMLHttpRequest are named different as well.

Thank You in advance!