XMLHttpRequest to grab database values (Wordpress) - php

Question

I'm having issues getting my local Wordpress installation to properly grab data from a database. Im using xmlhttprequest to call a php file which has my database request and then sends it back. This all works on my local installation without Wordpress but once i moved it all over to a locla Wordpress im not getting any information back.
I was able to successfully add the Javascript XMLHttpRequest function to my php template and the function is called properly when I use the onchange event on dropdown select but doesnt seem to want to go over the other php request and start the db connection. Looking for any thoughts...thanks!
Drop down select on Index.php
<form method="get" action="./gardenguide.php">
<table>
<tr>
<td>Hardiness Zone</td>
<td>
<select name="zone" style="width:110px;" onchange="getVegetablesByZone(this.value)">
<option selected disabled>Select</option>
<option value="2a">Zone 2a</option>
<option value="2b">Zone 2b</option>
<option value="3a">Zone 3a</option>
<option value="3b">Zone 3b</option>
<option value="4a">Zone 4a</option>
<option value="4b">Zone 4b</option>
<option value="5a">Zone 5a</option>
<option value="5b">Zone 5b</option>
<option value="6a">Zone 6a</option>
<option value="6b">Zone 6b</option>
<option value="7a">Zone 7a</option>
<option value="7b">Zone 7b</option>
<option value="8a">Zone 8a</option>
<option value="8b">Zone 8b</option>
<option value="9a">Zone 9a</option>
<option value="9b">Zone 9b</option>
<option value="10a">Zone 10a</option>
<option value="10b">Zone 10b</option>
<option value="11a">Zone 11a</option>
<option value="11b">Zone 11b</option>
<option value="12a">Zone 12a</option>
<option value="12b">Zone 12b</option>
<option value="13a">Zone 13a</option>
<option value="13b">Zone 13b</option>
</select>
</td>
</tr>
</table>
<div id="results"><b></b></div>
</form>
JavaScript calling the XMLHTTP Request
function getVegetablesByZone(zone) {
if (zone == "") {
document.getElementById("results").innerHTML = "";
alert("works1");
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("results").innerHTML = xmlhttp.responseText;
}
};
}
PHP called from Javascript
<?php
$q = $_GET['q'];
echo "LOL";
$con = mysqli_connect('localhost','user','pass');
if (!$con) {
die('Could not connect: ' . mysqli_error($con));
}
mysqli_select_db($con,"plants");
$sql="SELECT plant_name FROM plants WHERE plant_id IN (SELECT fk_plant_id from hardinesszone WHERE zone = '$q')";
$result = mysqli_query($con,$sql);
if (!$result) {
printf("Error: %s\n", mysqli_error($con));
exit();
}
$display = "<table cellpadding=1 cellspacing=1 border=1>
<tr>";
$i=0;
while($row = mysqli_fetch_array($result)) {
if ($i < 3)
{
$display.= "<td><input type=\"checkbox\" name=\"v[]\" value=\"".$row['plant_name']."\"> " . $row['plant_name'] . "</td>";
}
else
{
$display.= "</tr><tr><td><input type=\"checkbox\" name=\"v[]\" value=\"".$row['plant_name']."\"> " . $row['plant_name'] . "</td>";
$i=0;
}
$i=$i+1;
}
$display .= "</tr></table>";
$display .= "<input type=\"submit\" class=\"btn btn-submit btn-lg\" id=\"submit\" value=\"Submit!\">";
echo $display;
mysqli_close($con);
?>