通过ajax POST向PHP发送两个值以查询SQL db

Question

I'm trying to send two values from a form to another PHP using ajax post method. One value is the value that's already entered in an input box, and the other is a value that is being typed into another input box. It acts like a search box. I tried executing the SQL query in my SQL workbench and it returns the value properly. What am I doing wrong in my code?

function searchq6(){
    var searchstate = $("input[name='region']").val();
    var searchTxt = $("input[name='suburb']").val();
    $.post("search-suburb.php", {searchVal: searchTxt, st:searchstate},function(sbb){
        $("#sbb").html(sbb);
    //searchq7();
    });

}

This is the input box where I search and get the value from:

<input type="text" name="region" list="state" value="<?php echo $region;  ?>" placeholder="Select State" id="output">
Suburb:
        <input type="text" name="suburb" list="sbb" value="<?php echo $suburb;  ?>" onkeyup="searchq6()" id="output">
        <datalist id="sbb" name="taskoption6" >
                <option> </option>
        </datalist>

This is the search-suburb.php file:

$output = '' ;
if (isset($_POST['searchVal'])){
$searchq = $_POST['searchVal'];
$st = $_POST['st'];
$query = mysqli_query($link, "SELECT DISTINCT title FROM `wp_locations`  WHERE state="'.$st.'"  AND `title` LIKE  '%".$searchq."%' ")or die("Could not  search!");
$count = mysqli_num_rows($query);
if($count == 0){
    $output = '<option>No results!</option>';
}else{
while($row = mysqli_fetch_array($query)){
    $suburb = $row['title'];

?>
    <option value="<?php echo $suburb; ?>"><?php echo $suburb; ?>  </option>
<?php
} // while
} // else
} // main if

Answer 1

Got the answer from small snippets gathered through the comments Changed the query to:

$query = mysqli_query($link, "SELECT DISTINCT title FROM `wp_locations` WHERE state='".$st."'  AND `title` LIKE  '%".$searchq."%' LIMIT 10")or die("Could not search!");

And the ajax to:

function searchq6(){
    var searchstate = $("input[name='region']").val();
    var searchTxt = $("input[name='suburb']").val();
    $.post("search-suburb.php", {searchVal: searchTxt, st:searchstate})
    .done(function(sbb) {
        $("#sbb").html(sbb);
    });
    //searchq7();
}

Thanks for all the comments guys