making an ajax request from a multi query search form

[olawole.famakin]

hello i am trying implement a multi search query using an example i found online,

http://www.w3schools.com/php/php_ajax_database.asp

although the example on this page is a single query and makes use of a select menu, i have edited the code to make use of it using a textfield, and it works perfectly,
now am trying to make this one query to function as a multiquery form. but i keep gettin an exception

Notice: Undefined index: q in C:\xampp\htdocs\transportapp\getuser.php on line 2

this is the code that works as a single query

html file :

<script>
function showUser(str) {
    if (str == "") {
        document.getElementById("txtHint").innerHTML = "";
        return;
    } else { 
        if (window.XMLHttpRequest) {
            // code for IE7+, Firefox, Chrome, Opera, Safari
            xmlhttp = new XMLHttpRequest();
        } else {
            // code for IE6, IE5
            xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");
        }
        xmlhttp.onreadystatechange = function() {
            if (xmlhttp.readyState == 4 && xmlhttp.status == 200) {
                document.getElementById("txtHint").innerHTML = xmlhttp.responseText;
            }
        }
        xmlhttp.open("GET","getuser.php?q="+str,true);
        xmlhttp.send();
    }
}

</script>

<form>

  <input name="users" type="text" onKeyUp="showUser(this.value)">

</form>

php file :

<?php
$q = ($_GET['q']);



$con = mysqli_connect('localhost','root','famakin','wcp');
if (!$con) {
  die('Could not connect: ' . mysqli_error($con));
}

mysqli_select_db($con,"wcp");
$sql="SELECT * FROM user WHERE name = '".$q."'";
$result = mysqli_query($con,$sql);

and this what i have tried doin wen trying to convert to a multiquery

html file :

<script>
function showUser(str) {
    if (str == "") {
        document.getElementById("txtHint").innerHTML = "";
        return;
    } else { 
        if (window.XMLHttpRequest) {
            // code for IE7+, Firefox, Chrome, Opera, Safari
            xmlhttp = new XMLHttpRequest();
        } else {
            // code for IE6, IE5
            xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");
        }
        xmlhttp.onreadystatechange = function() {
            if (xmlhttp.readyState == 4 && xmlhttp.status == 200) {
                document.getElementById("txtHint").innerHTML = xmlhttp.responseText;
            }
        }
        xmlhttp.open("GET","getuser.php?q="+str,true);
        xmlhttp.open("GET","getuser.php?k="+str,true);

        xmlhttp.send();
    }
}
</script>

<form>

  <input name="users" type="text" onKeyUp="showUser(this.value)">
    <input name="user" type="text" onKeyUp="showUser(this.value)">
</form>
<br>
<div id="txtHint"><b>Person info will be listed here.</b></div>

php file :

<?php
$q = ($_GET['q']);
$k = ($_GET['k']);



$con = mysqli_connect('localhost','root','famakin','wcp');
if (!$con) {
  die('Could not connect: ' . mysqli_error($con));
}

mysqli_select_db($con,"wcp");
$sql="SELECT * FROM user WHERE name = '".$q."' and username = '".$k."'";
$result = mysqli_query($con,$sql);

and then i get this error Notice: Undefined index: q in C:\xampp\htdocs\transportapp\getuser.php on line 2

i am confused on why am gettin this error. my aim is to pass multiple values via ajax request and query my database

[broj1]

If you want to pass multiple values you can do it this way:

xmlhttp.open("GET","getuser.php?q="+str+"&k="+somevalue,true);

In this case you will always have both q and k elements in the $_GET array. But it is a question of what you really intend to do. Maybe some other approach is more appropriate.