$wpdb->get_var is not working

In my code $wpdb->get_var is not working and it always shows “Country is not available for delivery”. Please help. Here is my code.

<form method="post" action="<?php $_SERVER["PHP_SELF"]; ?>">
                Country:
                <select name="country" id="country">
                    <option value="">Select Country</option>
                    <?php
                    global $wpdb;
                    $results = $wpdb->get_results("SELECT kcsc.country_fullname FROM KCS_country kcsc,wpws_woocommerce_shipping_zone_locations wszl where kcsc.country_code=wszl.location_code and wszl.location_type='country' order by wszl.location_code");
                    foreach ($results as $res) {
                        ?>
                        <option value="<?php echo $res2->country_fullname; ?>"><?php echo $res->country_fullname; ?></option>
                        <?php
                    }
                    ?>
                </select>
                <input type="submit" name="country_submit" value="Submit">
            </form>
        </div>

        <?php
        if (isset($_POST["country_submit"])) {
            global $wpdb;
            $country = $_POST['country'];
            $myrow2 = $wpdb->get_var("select wszl.location_code from wpws_woocommerce_shipping_zone_locations wszl,KCS_country kcsc where kcsc.country_code=wszl.location_code and kcsc.country_fullname='".$country."'");
            if ($myrow2){
            echo "Country is available for delivery";
           }
           else
                echo "Country is not available for delivery";
        }
        ?>